$TMUS
T-Mobile US, Inc. Stock $tmus

$tmus Overview Financials Valuation SEC Filings Company Website

2020 Q4 Form 10-K Financial Statement

#000128369921000039 Filed on February 23, 2021

Income Statement

Concept	2020 Q4	2020	2019 Q4
Revenue	$20.34B	$68.40B	$11.88B
YoY Change	71.25%	52.0%	3.78%
Cost Of Revenue	$9.119B	$27.61B	$5.212B
YoY Change	74.96%	49.1%	0.81%
Gross Profit	$11.22B	$40.78B	$6.666B
YoY Change	68.35%	54.03%	6.23%
Gross Profit Margin	55.17%	59.63%	56.12%
Selling, General & Admin	$4.605B	$18.93B	$3.530B
YoY Change	30.45%	33.86%	0.91%
% of Gross Profit	41.04%	46.41%	52.96%
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$4.219B	$14.15B	$1.776B
YoY Change	137.56%	113.89%	8.29%
% of Gross Profit	37.6%	34.7%	26.64%
Operating Expenses	$8.824B	$18.93B	$5.306B
YoY Change	66.3%	33.86%	3.27%
Operating Profit	$1.712B	$6.636B	$1.234B
YoY Change	38.74%	15.97%	8.53%
Interest Expense	-$790.0M	-$2.701B	-$273.0M
YoY Change	189.38%	143.11%	-7.77%
% of Operating Profit	-46.14%	-40.7%	-22.12%
Other Income/Expense, Net	-$101.0M	-$3.106B	$4.000M
YoY Change	-2625.0%	177.57%	-233.33%
Pretax Income	$821.0M	$3.530B	$965.0M
YoY Change	-14.92%	-23.31%	15.16%
Income Tax	$71.00M	$786.0M	$214.0M
% Of Pretax Income	8.65%	22.27%	22.18%
Net Earnings	$750.0M	$3.064B	$751.0M
YoY Change	-0.13%	-11.65%	17.34%
Net Earnings / Revenue	3.69%	4.48%	6.32%
Basic Earnings Per Share	$0.60	$2.68	$0.88
Diluted Earnings Per Share	$0.60	$2.65	$0.87
COMMON SHARES
Basic Shares Outstanding	1.242B shares	1.144B shares	856.3M shares
Diluted Shares Outstanding	1.252B shares	1.155B shares	864.2M shares

Balance Sheet

Concept	2020 Q4	2020	2019 Q4
SHORT-TERM ASSETS
Cash & Short-Term Investments	$10.39B	$10.39B	$1.528B
YoY Change	579.65%	579.65%	27.02%
Cash & Equivalents	$10.39B	$10.39B	$1.528B
Short-Term Investments
Other Short-Term Assets	$2.496B	$2.842B	$1.972B
YoY Change	26.57%	26.76%	17.66%
Inventory	$2.527B	$2.527B	$964.0M
Prepaid Expenses	$624.0M		$333.0M
Receivables	$4.254B	$4.532B	$1.888B
Other Receivables	$3.599B	$3.599B	$2.620B
Total Short-Term Assets	$23.89B	$23.89B	$9.305B
YoY Change	156.69%	156.69%	12.37%
LONG-TERM ASSETS
Property, Plant & Equipment	$41.18B	$72.22B	$21.98B
YoY Change	87.3%	102.69%	-5.89%
Goodwill	$11.12B		$1.930B
YoY Change	476.01%		1.53%
Intangibles
YoY Change
Long-Term Investments
YoY Change
Other Assets	$2.779B	$2.779B	$1.891B
YoY Change	46.96%	46.96%	16.51%
Total Long-Term Assets	$176.3B	$176.3B	$77.62B
YoY Change	127.11%	127.11%	20.92%
TOTAL ASSETS
Total Short-Term Assets	$23.89B	$23.89B	$9.305B
Total Long-Term Assets	$176.3B	$176.3B	$77.62B
Total Assets	$200.2B	$200.2B	$86.92B
YoY Change	130.28%	130.28%	19.94%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$5.564B	$5.564B	$6.746B
YoY Change	-17.52%	28.74%	-12.85%
Accrued Expenses	$8.500B	$8.500B	$2.287B
YoY Change	271.67%	80.43%
Deferred Revenue	$1.030B		$631.0M
YoY Change	63.23%		-9.6%
Short-Term Debt	$4.579B	$4.579B	$25.00M
YoY Change	18216.0%		-97.03%
Long-Term Debt Due	$4.579B	$1.063B	$25.00M
YoY Change	18216.0%	8.25%	-97.03%
Total Short-Term Liabilities	$21.70B	$21.70B	$12.51B
YoY Change	73.54%	73.54%	21.81%
LONG-TERM LIABILITIES
Long-Term Debt	$61.83B	$71.02B	$10.96B
YoY Change	464.25%	148.96%	-9.62%
Other Long-Term Liabilities	$5.412B	$32.13B	$954.0M
YoY Change	467.3%	179.57%	-1.34%
Total Long-Term Liabilities	$113.1B	$103.1B	$45.63B
YoY Change	147.92%	157.75%	21.72%
TOTAL LIABILITIES
Total Short-Term Liabilities	$21.70B	$21.70B	$12.51B
Total Long-Term Liabilities	$113.1B	$103.1B	$45.63B
Total Liabilities	$134.8B	$134.8B	$58.13B
YoY Change	131.92%	131.92%	21.74%
SHAREHOLDERS EQUITY
Retained Earnings	-$5.836B		-$8.833B
YoY Change	-33.93%		-31.81%
Common Stock	$72.77B		$38.50B
YoY Change	89.03%		1.28%
Preferred Stock
YoY Change
Treasury Stock (at cost)	$11.00M		$8.000M
YoY Change	37.5%		33.33%
Treasury Stock Shares	1.540M shares		1.513M shares
Shareholders Equity	$65.34B	$65.34B	$28.79B
YoY Change
Total Liabilities & Shareholders Equity	$200.2B	$200.2B	$86.92B
YoY Change	130.28%	130.28%	19.94%

Cashflow Statement

Concept	2020 Q4	2020	2019 Q4
OPERATING ACTIVITIES
Net Income	$750.0M	$3.064B	$751.0M
YoY Change	-0.13%	-11.65%	17.34%
Depreciation, Depletion And Amortization	$4.219B	$14.15B	$1.776B
YoY Change	137.56%	113.89%	8.29%
Cash From Operating Activities	$3.474B	$8.640B	$1.537B
YoY Change	126.02%	26.61%	61.11%
INVESTING ACTIVITIES
Capital Expenditures	-$3.807B	$11.03B	-$1.261B
YoY Change	201.9%	72.65%	4.21%
Acquisitions		$5.000B
YoY Change		16029.03%
Other Investing Activities	$160.0M	$338.0M	$374.0M
YoY Change	-57.22%	1777.78%	-74.05%
Cash From Investing Activities	-$3.647B	-$12.72B	-$887.0M
YoY Change	311.16%	208.24%	-483.98%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net		-$304.0M
YoY Change
Debt Paid & Issued, Net		$20.42B
YoY Change		3302.67%
Cash From Financing Activities	3.979B	$13.01B	-775.0M
YoY Change	-613.42%	-648.02%	149.2%
NET CHANGE
Cash From Operating Activities	3.474B	$8.640B	1.537B
Cash From Investing Activities	-3.647B	-$12.72B	-887.0M
Cash From Financing Activities	3.979B	$13.01B	-775.0M
Net Change In Cash	3.806B	$8.935B	-125.0M
YoY Change	-3144.8%	2649.23%	-114.3%
FREE CASH FLOW
Cash From Operating Activities	$3.474B	$8.640B	$1.537B
Capital Expenditures	-$3.807B	$11.03B	-$1.261B
Free Cash Flow	$7.281B	-$2.394B	$2.798B
YoY Change	160.22%	-652.89%	29.3%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
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CY2020	dei	Amendment Flag AmendmentFlag	false
CY2020	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2020
CY2020	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	FY
CY2020	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
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CY2020Q4	us-gaap	Revenue Remaining Performance Obligation Expected Timing Of Satisfaction Period1 RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1
CY2020	dei	Document Type DocumentType	10-K
CY2020	dei	Document Annual Report DocumentAnnualReport	true
CY2020	dei	Document Period End Date DocumentPeriodEndDate	2020-12-31
CY2020	dei	Document Transition Report DocumentTransitionReport	false
CY2020	dei	Entity File Number EntityFileNumber	1-33409
CY2020	dei	Entity Registrant Name EntityRegistrantName	T-MOBILE US, INC.
CY2020	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	DE
CY2020	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	20-0836269
CY2020	dei	Entity Address Address Line1 EntityAddressAddressLine1	12920 SE 38th Street
CY2020	dei	Entity Address City Or Town EntityAddressCityOrTown	Bellevue
CY2020	dei	Entity Address State Or Province EntityAddressStateOrProvince	WA
CY2020	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	98006-1350
CY2020	dei	City Area Code CityAreaCode	(425)
CY2020	dei	Local Phone Number LocalPhoneNumber	378-4000
CY2020	dei	Security12b Title Security12bTitle	Common Stock, par value $0.00001 per share
CY2020	dei	Trading Symbol TradingSymbol	TMUS
CY2020	dei	Security Exchange Name SecurityExchangeName	NASDAQ
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CY2020	dei	Entity Voluntary Filers EntityVoluntaryFilers	No
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CY2020	dei	Entity Interactive Data Current EntityInteractiveDataCurrent	Yes
CY2020	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
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CY2020	us-gaap	Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest	2744000000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest	3468000000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest	2888000000	USD
CY2020	us-gaap	Income Loss From Discontinued Operations Net Of Tax IncomeLossFromDiscontinuedOperationsNetOfTax	320000000	USD
CY2019	us-gaap	Income Loss From Discontinued Operations Net Of Tax IncomeLossFromDiscontinuedOperationsNetOfTax	0	USD
CY2018	us-gaap	Income Loss From Discontinued Operations Net Of Tax IncomeLossFromDiscontinuedOperationsNetOfTax	0	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	3064000000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	3468000000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	2888000000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	3064000000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	3468000000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	2888000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Tax Parent OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTaxParent	-250000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Tax Parent OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTaxParent	-187000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Tax Parent OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTaxParent	-115000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax Parent OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTaxParent	-723000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax Parent OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTaxParent	-536000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax Parent OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTaxParent	-332000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax	1000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax	0	USD
CY2018	us-gaap	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax	0	USD
CY2020	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	4000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	0	USD
CY2018	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	0	USD
CY2020	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax	-2000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax	0	USD
CY2018	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax	0	USD
CY2020	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-6000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	0	USD
CY2018	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	0	USD
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-713000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-536000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-332000000	USD
CY2020	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	2351000000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	2.40
CY2019	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	2932000000	USD
CY2018	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	2556000000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	4.06
CY2018	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	3.40
CY2020	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0.28
CY2019	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0
CY2018	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0
CY2020	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.68
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	4.06
CY2018	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.40
CY2020	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	2.37
CY2019	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	4.02
CY2018	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	3.36
CY2020	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0.28
CY2019	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0
CY2018	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0
CY2020	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.65
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	4.02
CY2018	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.36
CY2020	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	1144206326	shares
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	854143751	shares
CY2018	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	849744152	shares
CY2020	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	1154749428	shares
CY2019	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	863433511	shares
CY2018	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	858290174	shares
CY2020	us-gaap	Net Income Loss NetIncomeLoss	3064000000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	3468000000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	2888000000	USD
CY2020	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	14151000000	USD
CY2019	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	6616000000	USD
CY2018	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	6486000000	USD
CY2020	us-gaap	Share Based Compensation ShareBasedCompensation	694000000	USD
CY2019	us-gaap	Share Based Compensation ShareBasedCompensation	495000000	USD
CY2018	us-gaap	Share Based Compensation ShareBasedCompensation	424000000	USD
CY2020	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	822000000	USD
CY2019	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	1091000000	USD
CY2018	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	980000000	USD
CY2020	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	602000000	USD
CY2019	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	307000000	USD
CY2018	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	297000000	USD
CY2020	us-gaap	Securitization Financial Asset For Which Transfer Is Accounted As Sale Gain Loss On Sale SecuritizationFinancialAssetForWhichTransferIsAccountedAsSaleGainLossOnSale	-36000000	USD
CY2019	us-gaap	Securitization Financial Asset For Which Transfer Is Accounted As Sale Gain Loss On Sale SecuritizationFinancialAssetForWhichTransferIsAccountedAsSaleGainLossOnSale	-130000000	USD
CY2020	us-gaap	Increase Decrease In Inventories IncreaseDecreaseInInventories	2222000000	USD
CY2018	us-gaap	Securitization Financial Asset For Which Transfer Is Accounted As Sale Gain Loss On Sale SecuritizationFinancialAssetForWhichTransferIsAccountedAsSaleGainLossOnSale	-157000000	USD
CY2020	us-gaap	Increase Decrease In Other Deferred Liability IncreaseDecreaseInOtherDeferredLiability	0	USD
CY2019	us-gaap	Increase Decrease In Other Deferred Liability IncreaseDecreaseInOtherDeferredLiability	0	USD
CY2018	us-gaap	Increase Decrease In Other Deferred Liability IncreaseDecreaseInOtherDeferredLiability	26000000	USD
CY2020	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	-371000000	USD
CY2019	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	-19000000	USD
CY2018	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	-122000000	USD
CY2020	us-gaap	Asset Impairment Charges AssetImpairmentCharges	418000000	USD
CY2019	us-gaap	Asset Impairment Charges AssetImpairmentCharges	0	USD
CY2018	us-gaap	Asset Impairment Charges AssetImpairmentCharges	0	USD
CY2020	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	3273000000	USD
CY2019	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	3709000000	USD
CY2018	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	4617000000	USD
CY2020	us-gaap	Increase Decrease In Finance Receivables IncreaseDecreaseInFinanceReceivables	1453000000	USD
CY2019	us-gaap	Increase Decrease In Finance Receivables IncreaseDecreaseInFinanceReceivables	1015000000	USD
CY2018	us-gaap	Increase Decrease In Finance Receivables IncreaseDecreaseInFinanceReceivables	1598000000	USD
CY2019	us-gaap	Increase Decrease In Inventories IncreaseDecreaseInInventories	617000000	USD
CY2018	us-gaap	Increase Decrease In Inventories IncreaseDecreaseInInventories	201000000	USD
CY2020	tmus	Increase Decreasein Operating Lease Rightof Use Asset IncreaseDecreaseinOperatingLeaseRightofUseAsset	-3465000000	USD
CY2019	tmus	Increase Decreasein Operating Lease Rightof Use Asset IncreaseDecreaseinOperatingLeaseRightofUseAsset	-1896000000	USD
CY2018	tmus	Increase Decreasein Operating Lease Rightof Use Asset IncreaseDecreaseinOperatingLeaseRightofUseAsset	0	USD
CY2020	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	402000000	USD
CY2019	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	144000000	USD
CY2018	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	181000000	USD
CY2020	us-gaap	Increase Decrease In Accounts Payable And Accrued Liabilities IncreaseDecreaseInAccountsPayableAndAccruedLiabilities	-2123000000	USD
CY2019	us-gaap	Increase Decrease In Accounts Payable And Accrued Liabilities IncreaseDecreaseInAccountsPayableAndAccruedLiabilities	17000000	USD
CY2018	us-gaap	Increase Decrease In Accounts Payable And Accrued Liabilities IncreaseDecreaseInAccountsPayableAndAccruedLiabilities	-867000000	USD
CY2020	tmus	Increase Decreasein Operating Lease Liability IncreaseDecreaseinOperatingLeaseLiability	-3699000000	USD
CY2019	tmus	Increase Decreasein Operating Lease Liability IncreaseDecreaseinOperatingLeaseLiability	-2131000000	USD
CY2018	tmus	Increase Decreasein Operating Lease Liability IncreaseDecreaseinOperatingLeaseLiability	0	USD
CY2020	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	-2178000000	USD
CY2019	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	144000000	USD
CY2018	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	-69000000	USD
CY2020	us-gaap	Other Operating Activities Cash Flow Statement OtherOperatingActivitiesCashFlowStatement	367000000	USD
CY2019	us-gaap	Other Operating Activities Cash Flow Statement OtherOperatingActivitiesCashFlowStatement	257000000	USD
CY2018	us-gaap	Other Operating Activities Cash Flow Statement OtherOperatingActivitiesCashFlowStatement	52000000	USD
CY2020	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	8640000000	USD
CY2019	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	6824000000	USD
CY2018	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	3899000000	USD
CY2020	us-gaap	Interest Costs Capitalized InterestCostsCapitalized	440000000	USD
CY2019	us-gaap	Interest Costs Capitalized InterestCostsCapitalized	473000000	USD
CY2018	us-gaap	Interest Costs Capitalized InterestCostsCapitalized	362000000	USD
CY2020	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	11034000000	USD
CY2019	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	6391000000	USD
CY2018	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	5541000000	USD
CY2020	us-gaap	Payments To Acquire Intangible Assets PaymentsToAcquireIntangibleAssets	1333000000	USD
CY2019	us-gaap	Payments To Acquire Intangible Assets PaymentsToAcquireIntangibleAssets	967000000	USD
CY2018	us-gaap	Payments To Acquire Intangible Assets PaymentsToAcquireIntangibleAssets	127000000	USD
CY2020	tmus	Proceeds From Sales Of Tower Sites ProceedsFromSalesOfTowerSites	0	USD
CY2019	tmus	Proceeds From Sales Of Tower Sites ProceedsFromSalesOfTowerSites	38000000	USD
CY2018	tmus	Proceeds From Sales Of Tower Sites ProceedsFromSalesOfTowerSites	0	USD
CY2020	us-gaap	Proceeds From Collection Of Retained Interest In Securitized Receivables ProceedsFromCollectionOfRetainedInterestInSecuritizedReceivables	3134000000	USD
CY2019	us-gaap	Proceeds From Collection Of Retained Interest In Securitized Receivables ProceedsFromCollectionOfRetainedInterestInSecuritizedReceivables	3876000000	USD
CY2018	us-gaap	Proceeds From Collection Of Retained Interest In Securitized Receivables ProceedsFromCollectionOfRetainedInterestInSecuritizedReceivables	5406000000	USD
CY2020	us-gaap	Payments For Proceeds From Hedge Investing Activities PaymentsForProceedsFromHedgeInvestingActivities	-632000000	USD
CY2019	us-gaap	Payments For Proceeds From Hedge Investing Activities PaymentsForProceedsFromHedgeInvestingActivities	632000000	USD
CY2018	us-gaap	Payments For Proceeds From Hedge Investing Activities PaymentsForProceedsFromHedgeInvestingActivities	0	USD
CY2020	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	5000000000	USD
CY2019	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	31000000	USD
CY2018	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	338000000	USD
CY2020	us-gaap	Proceeds From Divestiture Of Businesses Net Of Cash Divested ProceedsFromDivestitureOfBusinessesNetOfCashDivested	1224000000	USD
CY2019	us-gaap	Proceeds From Divestiture Of Businesses Net Of Cash Divested ProceedsFromDivestitureOfBusinessesNetOfCashDivested	0	USD
CY2018	us-gaap	Proceeds From Divestiture Of Businesses Net Of Cash Divested ProceedsFromDivestitureOfBusinessesNetOfCashDivested	0	USD
CY2020	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	338000000	USD
CY2019	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	18000000	USD
CY2018	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	-21000000	USD
CY2020	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-12715000000	USD
CY2019	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-4125000000	USD
CY2018	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-579000000	USD
CY2020	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	35337000000	USD
CY2019	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	0	USD
CY2018	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	2494000000	USD
CY2020	us-gaap	Payments Of Financing Costs PaymentsOfFinancingCosts	109000000	USD
CY2019	us-gaap	Payments Of Financing Costs PaymentsOfFinancingCosts	0	USD
CY2018	us-gaap	Payments Of Financing Costs PaymentsOfFinancingCosts	0	USD
CY2020	us-gaap	Proceeds From Secured Lines Of Credit ProceedsFromSecuredLinesOfCredit	0	USD
CY2019	us-gaap	Proceeds From Secured Lines Of Credit ProceedsFromSecuredLinesOfCredit	2340000000	USD
CY2018	us-gaap	Proceeds From Secured Lines Of Credit ProceedsFromSecuredLinesOfCredit	6265000000	USD
CY2020	us-gaap	Repayments Of Lines Of Credit RepaymentsOfLinesOfCredit	0	USD
CY2019	us-gaap	Repayments Of Lines Of Credit RepaymentsOfLinesOfCredit	2340000000	USD
CY2018	us-gaap	Repayments Of Lines Of Credit RepaymentsOfLinesOfCredit	6265000000	USD
CY2020	us-gaap	Finance Lease Principal Payments FinanceLeasePrincipalPayments	1021000000	USD
CY2019	us-gaap	Finance Lease Principal Payments FinanceLeasePrincipalPayments	798000000	USD
CY2018	us-gaap	Repayments Of Long Term Capital Lease Obligations RepaymentsOfLongTermCapitalLeaseObligations	700000000	USD
CY2020	tmus	Repayments Of Short Term Debt For Purchases Of Inventory Property And Equipment Net RepaymentsOfShortTermDebtForPurchasesOfInventoryPropertyAndEquipmentNet	481000000	USD
CY2019	tmus	Repayments Of Short Term Debt For Purchases Of Inventory Property And Equipment Net RepaymentsOfShortTermDebtForPurchasesOfInventoryPropertyAndEquipmentNet	775000000	USD
CY2018	tmus	Repayments Of Short Term Debt For Purchases Of Inventory Property And Equipment Net RepaymentsOfShortTermDebtForPurchasesOfInventoryPropertyAndEquipmentNet	300000000	USD
CY2020	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	20416000000	USD
CY2019	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	600000000	USD
CY2018	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	3349000000	USD
CY2020	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	19840000000	USD
CY2019	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	0	USD
CY2018	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	0	USD
CY2020	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	19536000000	USD
CY2020	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	19536000000	USD
CY2019	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	0	USD
CY2018	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	1071000000	USD
CY2020	us-gaap	Proceeds From Short Term Debt ProceedsFromShortTermDebt	18743000000	USD
CY2019	us-gaap	Proceeds From Short Term Debt ProceedsFromShortTermDebt	0	USD
CY2018	us-gaap	Proceeds From Short Term Debt ProceedsFromShortTermDebt	0	USD
CY2020	us-gaap	Repayments Of Other Short Term Debt RepaymentsOfOtherShortTermDebt	18929000000	USD
CY2019	us-gaap	Repayments Of Other Short Term Debt RepaymentsOfOtherShortTermDebt	0	USD
CY2018	us-gaap	Repayments Of Other Short Term Debt RepaymentsOfOtherShortTermDebt	0	USD
CY2020	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	439000000	USD
CY2019	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	156000000	USD
CY2018	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	146000000	USD
CY2020	us-gaap	Payments Of Debt Extinguishment Costs PaymentsOfDebtExtinguishmentCosts	82000000	USD
CY2019	us-gaap	Payments Of Debt Extinguishment Costs PaymentsOfDebtExtinguishmentCosts	28000000	USD
CY2018	us-gaap	Payments Of Debt Extinguishment Costs PaymentsOfDebtExtinguishmentCosts	212000000	USD
CY2020	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	103000000	USD
CY2019	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	-17000000	USD
CY2018	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	-52000000	USD
CY2020	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	13010000000	USD
CY2019	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-2374000000	USD
CY2018	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-3336000000	USD
CY2020	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	8935000000	USD
CY2019	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	325000000	USD
CY2018	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-16000000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	1528000000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	1203000000	USD
CY2017Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	1219000000	USD
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	10463000000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	1528000000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	1203000000	USD
CY2017Q4	us-gaap	Stockholders Equity StockholdersEquity	22559000000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	2888000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-332000000	USD
CY2018	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	473000000	USD
CY2018	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	3000000	USD
CY2018	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	103000000	USD
CY2018	us-gaap	Adjustments Related To Tax Withholding For Share Based Compensation AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation	146000000	USD
CY2018	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	1054000000	USD
CY2018	tmus	Prior Year Retained Earnings PriorYearRetainedEarnings	-224000000	USD
CY2018Q4	us-gaap	Stockholders Equity StockholdersEquity	24718000000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	3468000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-536000000	USD
CY2019	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	517000000	USD
CY2019	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	1000000	USD
CY2019	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	124000000	USD
CY2019	us-gaap	Adjustments Related To Tax Withholding For Share Based Compensation AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation	156000000	USD
CY2019	tmus	Transfer Rs Uto Nqdc Plan TransferRSUtoNQDCPlan	0	USD
CY2019	tmus	Prior Year Retained Earnings PriorYearRetainedEarnings	-653000000	USD
CY2019Q4	us-gaap	Stockholders Equity StockholdersEquity	28789000000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	3064000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-713000000	USD
CY2020	tmus	Adjustments To Additional Paid In Capital Executive Put Option AdjustmentsToAdditionalPaidInCapitalExecutivePutOption	1000000	USD
CY2020	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	750000000	USD
CY2020	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	48000000	USD
CY2020	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	148000000	USD
CY2020	us-gaap	Adjustments Related To Tax Withholding For Share Based Compensation AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation	439000000	USD
CY2020	tmus	Transfer Rs Uto Nqdc Plan TransferRSUtoNQDCPlan	0	USD
CY2020	us-gaap	Stock Issued During Period Value New Issues StockIssuedDuringPeriodValueNewIssues	19766000000	USD
CY2020	us-gaap	Stock Repurchased During Period Value StockRepurchasedDuringPeriodValue	19536000000	USD
CY2020	tmus	Adjustment To Additional Paid In Capital Purchase Price Consideration AdjustmentToAdditionalPaidInCapitalPurchasePriceConsideration	33533000000	USD
CY2020	tmus	Prior Year Retained Earnings PriorYearRetainedEarnings	67000000	USD
CY2020Q4	us-gaap	Stockholders Equity StockholdersEquity	65344000000	USD
CY2020	us-gaap	Use Of Estimates UseOfEstimates	Estimates are based on historical experience, where applicable, and other assumptions which our management believes are reasonable under the circumstances, including but not limited to the valuation of assets acquired and liabilities assumed through the Merger with Sprint and the potential impacts arising from the COVID-19 pandemic (the “Pandemic”). These estimates are inherently subject to judgment and actual results could differ from those estimates.
CY2020	us-gaap	Prior Period Reclassification Adjustment Description PriorPeriodReclassificationAdjustmentDescription	Certain prior year amounts have been reclassified to conform to the current year's presentation.
CY2020	tmus	Device Upgrade Period DeviceUpgradePeriod	P18M
CY2020	tmus	Device Upgrade Period DeviceUpgradePeriod	P18M
CY2020	us-gaap	Number Of Reporting Units NumberOfReportingUnits	2	unit
CY2020	tmus	Licenses Issued Fixed Period LicensesIssuedFixedPeriod	P15Y
CY2020	us-gaap	Number Of Reporting Units NumberOfReportingUnits	2	unit
CY2020	us-gaap	Derivatives Reporting Of Derivative Activity DerivativesReportingOfDerivativeActivity	<div><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%">Derivative Financial Instruments</span></div><div><span><br/></span></div><div><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">Derivative financial instruments are recognized as either assets or liabilities and are measured at fair value. We do not use derivatives for trading or speculative purposes.</span></div><div><span><br/></span></div><div><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">For derivative instruments designated as cash flow hedges associated with forecasted debt issuances, changes in fair value are reported as a component of Accumulated other comprehensive loss until reclassified into Interest expense in the same period the hedged transaction affects earnings, generally over the life of the related debt. Unrealized gains on derivatives designated in qualifying cash flow hedge relationships are recorded at fair value as assets, and unrealized losses are recorded at fair value as liabilities.</span></div>
CY2020	us-gaap	Excise And Sales Taxes ExciseAndSalesTaxes	267000000	USD
CY2019	us-gaap	Excise And Sales Taxes ExciseAndSalesTaxes	93000000	USD
CY2018	us-gaap	Excise And Sales Taxes ExciseAndSalesTaxes	161000000	USD
CY2020	tmus	Device Upgrade Period DeviceUpgradePeriod	P18M
CY2020Q4	us-gaap	Capitalized Contract Cost Amortization Period CapitalizedContractCostAmortizationPeriod	P24M
CY2020	us-gaap	Advertising Expense AdvertisingExpense	1800000000	USD
CY2019	us-gaap	Advertising Expense AdvertisingExpense	1600000000	USD
CY2018	us-gaap	Advertising Expense AdvertisingExpense	1700000000	USD
CY2020Q2	us-gaap	Share Price SharePrice	83.90
CY2020	tmus	Numberof Portfolio Segments NumberofPortfolioSegments	2	segment
CY2020	tmus	Numberof Customer Classes NumberofCustomerClasses	2	class
CY2020Q4	us-gaap	Notes Receivable Gross NotesReceivableGross	6213000000	USD
CY2019Q4	us-gaap	Notes Receivable Gross NotesReceivableGross	4582000000	USD
CY2020Q4	us-gaap	Receivable With Imputed Interest Discount ReceivableWithImputedInterestDiscount	325000000	USD
CY2019Q4	us-gaap	Receivable With Imputed Interest Discount ReceivableWithImputedInterestDiscount	299000000	USD
CY2020Q4	us-gaap	Receivable With Imputed Interest Net Amount ReceivableWithImputedInterestNetAmount	5888000000	USD
CY2019Q4	us-gaap	Receivable With Imputed Interest Net Amount ReceivableWithImputedInterestNetAmount	4283000000	USD
CY2020Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	280000000	USD
CY2019Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	100000000	USD
CY2020Q4	us-gaap	Notes Receivable Net NotesReceivableNet	5608000000	USD
CY2019Q4	us-gaap	Notes Receivable Net NotesReceivableNet	4183000000	USD
CY2020Q4	us-gaap	Notes Receivable Net NotesReceivableNet	5608000000	USD
CY2019Q4	us-gaap	Notes Receivable Net NotesReceivableNet	4183000000	USD
CY2020Q4	us-gaap	Receivable With Imputed Interest Net Amount ReceivableWithImputedInterestNetAmount	5888000000	USD
CY2019Q4	tmus	Unamortized Imputed Discountand Allowancefor Credit Losses UnamortizedImputedDiscountandAllowanceforCreditLosses	460000000	USD
CY2018Q4	tmus	Unamortized Imputed Discountand Allowancefor Credit Losses UnamortizedImputedDiscountandAllowanceforCreditLosses	516000000	USD
CY2017Q4	tmus	Unamortized Imputed Discountand Allowancefor Credit Losses UnamortizedImputedDiscountandAllowanceforCreditLosses	482000000	USD
CY2020	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	602000000	USD
CY2019	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	307000000	USD
CY2018	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	297000000	USD
CY2020	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	380000000	USD
CY2019	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	332000000	USD
CY2018	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	328000000	USD
CY2020	tmus	Receivable With Imputed Interest Discount Increase Decrease ReceivableWithImputedInterestDiscountIncreaseDecrease	171000000	USD
CY2019	tmus	Receivable With Imputed Interest Discount Increase Decrease ReceivableWithImputedInterestDiscountIncreaseDecrease	136000000	USD
CY2018	tmus	Receivable With Imputed Interest Discount Increase Decrease ReceivableWithImputedInterestDiscountIncreaseDecrease	250000000	USD
CY2020	us-gaap	Financing Receivable Significant Sales FinancingReceivableSignificantSales	145000000	USD
CY2019	us-gaap	Financing Receivable Significant Sales FinancingReceivableSignificantSales	167000000	USD
CY2018	us-gaap	Financing Receivable Significant Sales FinancingReceivableSignificantSales	185000000	USD
CY2020Q4	tmus	Unamortized Imputed Discountand Allowancefor Credit Losses UnamortizedImputedDiscountandAllowanceforCreditLosses	799000000	USD
CY2019Q4	tmus	Unamortized Imputed Discountand Allowancefor Credit Losses UnamortizedImputedDiscountandAllowanceforCreditLosses	460000000	USD
CY2018Q4	tmus	Unamortized Imputed Discountand Allowancefor Credit Losses UnamortizedImputedDiscountandAllowanceforCreditLosses	516000000	USD
CY2020Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	42395000000	USD
CY2019Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	33118000000	USD
CY2020Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	41175000000	USD
CY2019Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	21984000000	USD
CY2020	us-gaap	Depreciation Depreciation	13100000000	USD
CY2019	us-gaap	Depreciation Depreciation	6500000000	USD
CY2018	us-gaap	Depreciation Depreciation	6400000000	USD
CY2020	tmus	Depreciation Expensefor Leased Wireless Devices DepreciationExpenseforLeasedWirelessDevices	3100000000	USD
CY2019	tmus	Depreciation Expensefor Leased Wireless Devices DepreciationExpenseforLeasedWirelessDevices	543000000	USD
CY2018	tmus	Depreciation Expensefor Leased Wireless Devices DepreciationExpenseforLeasedWirelessDevices	940000000	USD
CY2020	us-gaap	Interest Costs Capitalized InterestCostsCapitalized	440000000	USD
CY2019	us-gaap	Interest Costs Capitalized InterestCostsCapitalized	473000000	USD
CY2018	us-gaap	Interest Costs Capitalized InterestCostsCapitalized	362000000	USD
CY2019Q4	us-gaap	Asset Retirement Obligation AssetRetirementObligation	659000000	USD
CY2018Q4	us-gaap	Asset Retirement Obligation AssetRetirementObligation	609000000	USD
CY2020	tmus	Asset Retirement Obligation Liabilities Assumed In Business Combination AssetRetirementObligationLiabilitiesAssumedInBusinessCombination	1110000000	USD
CY2019	tmus	Asset Retirement Obligation Liabilities Assumed In Business Combination AssetRetirementObligationLiabilitiesAssumedInBusinessCombination	0	USD
CY2020	us-gaap	Asset Retirement Obligation Liabilities Incurred AssetRetirementObligationLiabilitiesIncurred	16000000	USD
CY2019	us-gaap	Asset Retirement Obligation Liabilities Incurred AssetRetirementObligationLiabilitiesIncurred	35000000	USD
CY2020	us-gaap	Asset Retirement Obligation Liabilities Settled AssetRetirementObligationLiabilitiesSettled	40000000	USD
CY2019	us-gaap	Asset Retirement Obligation Liabilities Settled AssetRetirementObligationLiabilitiesSettled	2000000	USD
CY2020	us-gaap	Asset Retirement Obligation Accretion Expense AssetRetirementObligationAccretionExpense	55000000	USD
CY2019	us-gaap	Asset Retirement Obligation Accretion Expense AssetRetirementObligationAccretionExpense	32000000	USD
CY2020	us-gaap	Asset Retirement Obligation Revision Of Estimate AssetRetirementObligationRevisionOfEstimate	17000000	USD
CY2019	us-gaap	Asset Retirement Obligation Revision Of Estimate AssetRetirementObligationRevisionOfEstimate	-15000000	USD
CY2020Q4	us-gaap	Asset Retirement Obligation AssetRetirementObligation	1817000000	USD
CY2019Q4	us-gaap	Asset Retirement Obligation AssetRetirementObligation	659000000	USD
CY2020Q4	us-gaap	Capitalized Costs Asset Retirement Costs CapitalizedCostsAssetRetirementCosts	912000000	USD
CY2019Q4	us-gaap	Capitalized Costs Asset Retirement Costs CapitalizedCostsAssetRetirementCosts	159000000	USD
CY2020	us-gaap	Capitalized Computer Software Impairments1 CapitalizedComputerSoftwareImpairments1	200000000	USD
CY2018	us-gaap	Capitalized Computer Software Impairments1 CapitalizedComputerSoftwareImpairments1	0	USD
CY2019	us-gaap	Capitalized Computer Software Impairments1 CapitalizedComputerSoftwareImpairments1	0	USD
CY2019Q4	us-gaap	Goodwill Impaired Accumulated Impairment Loss GoodwillImpairedAccumulatedImpairmentLoss	10766000000	USD
CY2019Q4	us-gaap	Goodwill Gross GoodwillGross	1901000000	USD
CY2019Q4	us-gaap	Goodwill Goodwill	1930000000	USD
CY2020	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	218000000	USD
CY2020Q4	us-gaap	Goodwill Goodwill	11117000000	USD
CY2020Q4	us-gaap	Goodwill Impaired Accumulated Impairment Loss GoodwillImpairedAccumulatedImpairmentLoss	10984000000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	6665000000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	1367000000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	5298000000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	1527000000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	1412000000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	115000000	USD
CY2019Q4	us-gaap	Debt Issuance Costs Line Of Credit Arrangements Net DebtIssuanceCostsLineOfCreditArrangementsNet	46000000	USD
CY2020	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	1200000000	USD
CY2019	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	82000000	USD
CY2018	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	124000000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Next Rolling Twelve Months FiniteLivedIntangibleAssetsAmortizationExpenseNextRollingTwelveMonths	1246000000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Rolling Year Two FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearTwo	982000000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Rolling Year Three FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearThree	827000000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Rolling Year Four FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearFour	669000000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Rolling Year Five FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearFive	511000000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Rolling After Year Five FiniteLivedIntangibleAssetsAmortizationExpenseRollingAfterYearFive	1063000000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	5298000000	USD
CY2020Q1	us-gaap	Payments For Proceeds From Hedge Investing Activities PaymentsForProceedsFromHedgeInvestingActivities	-580000000	USD
CY2019Q4	us-gaap	Payments For Proceeds From Hedge Investing Activities PaymentsForProceedsFromHedgeInvestingActivities	-632000000	USD
CY2020Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-1600000000	USD
CY2019Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-868000000	USD
CY2020Q4	us-gaap	Guarantee Obligations Current Carrying Value GuaranteeObligationsCurrentCarryingValue	50000000	USD
CY2019Q4	us-gaap	Guarantee Obligations Current Carrying Value GuaranteeObligationsCurrentCarryingValue	62000000	USD
CY2020Q4	us-gaap	Debt Instrument Unamortized Premium DebtInstrumentUnamortizedPremium	2197000000	USD
CY2019Q4	us-gaap	Debt Instrument Unamortized Premium DebtInstrumentUnamortizedPremium	0	USD
CY2020Q4	us-gaap	Debt Instrument Unamortized Discount DebtInstrumentUnamortizedDiscount	197000000	USD
CY2019Q4	us-gaap	Debt Instrument Unamortized Discount DebtInstrumentUnamortizedDiscount	0	USD
CY2020Q4	us-gaap	Debt Issuance Costs Line Of Credit Arrangements Net DebtIssuanceCostsLineOfCreditArrangementsNet	244000000	USD
CY2020Q4	us-gaap	Long Term Debt LongTermDebt	71125000000	USD
CY2019Q4	us-gaap	Long Term Debt LongTermDebt	24969000000	USD
CY2020Q4	us-gaap	Long Term Debt Current LongTermDebtCurrent	4579000000	USD
CY2019Q4	us-gaap	Long Term Debt Current LongTermDebtCurrent	25000000	USD
CY2020Q4	tmus	Longterm Debtand Longterm Debtto Affiliates LongtermDebtandLongtermDebttoAffiliates	66546000000	USD
CY2019Q4	tmus	Longterm Debtand Longterm Debtto Affiliates LongtermDebtandLongtermDebttoAffiliates	24944000000	USD
CY2020Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	61830000000	USD
CY2019Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	10958000000	USD
CY2020Q4	us-gaap	Due To Affiliate Noncurrent DueToAffiliateNoncurrent	4716000000	USD
CY2019Q4	us-gaap	Due To Affiliate Noncurrent DueToAffiliateNoncurrent	13986000000	USD
CY2020Q4	tmus	Longterm Debtand Longterm Debtto Affiliates LongtermDebtandLongtermDebttoAffiliates	66546000000	USD
CY2019Q4	tmus	Longterm Debtand Longterm Debtto Affiliates LongtermDebtandLongtermDebttoAffiliates	24944000000	USD
CY2020Q4	us-gaap	Debt Instrument Interest Rate Effective Percentage DebtInstrumentInterestRateEffectivePercentage	0.046
CY2019Q4	us-gaap	Debt Instrument Interest Rate Effective Percentage DebtInstrumentInterestRateEffectivePercentage	0.052
CY2020Q4	tmus	Debt Instrument Average Amount Outstanding During Period DebtInstrumentAverageAmountOutstandingDuringPeriod	58400000000	USD
CY2019Q4	tmus	Debt Instrument Average Amount Outstanding During Period DebtInstrumentAverageAmountOutstandingDuringPeriod	25500000000	USD
CY2020Q4	us-gaap	Debt Instrument Face Amount DebtInstrumentFaceAmount	54750000000	USD
CY2020Q4	us-gaap	Debt Instrument Unamortized Discount Premium And Debt Issuance Costs Net DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet	670000000	USD
CY2020	us-gaap	Proceeds From Issuance Of Senior Long Term Debt ProceedsFromIssuanceOfSeniorLongTermDebt	54080000000	USD
CY2020Q4	us-gaap	Proceeds From Issuance Of Senior Long Term Debt ProceedsFromIssuanceOfSeniorLongTermDebt	4000000000.0	USD
CY2020Q4	us-gaap	Proceeds From Issuance Of Senior Long Term Debt ProceedsFromIssuanceOfSeniorLongTermDebt	4600000000	USD
CY2020Q4	tmus	Debt Instrument Redeemed Face Amount DebtInstrumentRedeemedFaceAmount	9450000000	USD
CY2020	tmus	Write Off Of Premiums Discounts And Issuance Cost Redeemed WriteOffOfPremiumsDiscountsAndIssuanceCostRedeemed	10000000	USD
CY2020	tmus	Debt Instrument Redemption Premium Redeemed DebtInstrumentRedemptionPremiumRedeemed	58000000	USD
CY2020Q4	us-gaap	Debt Instrument Repurchased Face Amount DebtInstrumentRepurchasedFaceAmount	30447000000	USD
CY2020	tmus	Writeoffof Premiums Discountsand Issuance Costs WriteoffofPremiumsDiscountsandIssuanceCosts	351000000	USD
CY2020	tmus	Reimbursement Of Commitment Letter Fees ReimbursementOfCommitmentLetterFees	-47000000	USD
CY2020Q4	us-gaap	Letters Of Credit Outstanding Amount LettersOfCreditOutstandingAmount	555000000	USD
CY2019Q4	us-gaap	Letters Of Credit Outstanding Amount LettersOfCreditOutstandingAmount	113000000	USD
CY2020Q4	tmus	Minimum Lease Payments Failed Sale Leaseback Transaction Next Twelve Months MinimumLeasePaymentsFailedSaleLeasebackTransactionNextTwelveMonths	397000000	USD
CY2020Q4	tmus	Minimum Lease Payments Failed Sale Leaseback Transactions Within Two And Three Years MinimumLeasePaymentsFailedSaleLeasebackTransactionsWithinTwoAndThreeYears	716000000	USD
CY2020Q4	tmus	Minimum Lease Payments Failed Sale Leaseback Transactions Within Four And Five Years MinimumLeasePaymentsFailedSaleLeasebackTransactionsWithinFourAndFiveYears	598000000	USD
CY2020Q4	tmus	Minimum Lease Payments Failed Sale Leaseback Transactions Thereafter MinimumLeasePaymentsFailedSaleLeasebackTransactionsThereafter	624000000	USD
CY2019Q4	us-gaap	Contract With Customer Asset Net ContractWithCustomerAssetNet	63000000	USD
CY2019Q4	us-gaap	Contract With Customer Liability ContractWithCustomerLiability	560000000	USD
CY2020Q4	us-gaap	Contract With Customer Asset Net ContractWithCustomerAssetNet	278000000	USD
CY2020Q4	us-gaap	Contract With Customer Liability ContractWithCustomerLiability	824000000	USD
CY2020	us-gaap	Increase Decrease In Contract With Customer Asset IncreaseDecreaseInContractWithCustomerAsset	215000000	USD
CY2020	us-gaap	Increase Decrease In Contract With Customer Liability IncreaseDecreaseInContractWithCustomerLiability	264000000	USD
CY2020Q4	us-gaap	Contract With Customer Asset Net Current ContractWithCustomerAssetNetCurrent	204000000	USD
CY2019Q4	us-gaap	Contract With Customer Asset Net Current ContractWithCustomerAssetNetCurrent	50000000	USD
CY2020	us-gaap	Contract With Customer Liability Revenue Recognized ContractWithCustomerLiabilityRevenueRecognized	545000000	USD
CY2019	us-gaap	Contract With Customer Liability Revenue Recognized ContractWithCustomerLiabilityRevenueRecognized	643000000	USD
CY2020Q4	us-gaap	Revenue Remaining Performance Obligation RevenueRemainingPerformanceObligation	1300000000	USD
CY2020Q4	us-gaap	Revenue Remaining Performance Obligation RevenueRemainingPerformanceObligation	1100000000	USD
CY2020Q4	us-gaap	Revenue Remaining Performance Obligation RevenueRemainingPerformanceObligation	317000000	USD
CY2020Q4	us-gaap	Capitalized Contract Cost Net CapitalizedContractCostNet	1100000000	USD
CY2019Q4	us-gaap	Capitalized Contract Cost Net CapitalizedContractCostNet	906000000	USD
CY2020Q4	us-gaap	Capitalized Contract Cost Amortization Period CapitalizedContractCostAmortizationPeriod	P24M
CY2020	us-gaap	Capitalized Contract Cost Amortization CapitalizedContractCostAmortization	865000000	USD
CY2019	us-gaap	Capitalized Contract Cost Amortization CapitalizedContractCostAmortization	604000000	USD
CY2019	us-gaap	Capitalized Contract Cost Impairment Loss CapitalizedContractCostImpairmentLoss	0	USD
CY2020	us-gaap	Capitalized Contract Cost Impairment Loss CapitalizedContractCostImpairmentLoss	0	USD
CY2020	us-gaap	Share Based Compensation ShareBasedCompensation	694000000	USD
CY2019	us-gaap	Share Based Compensation ShareBasedCompensation	495000000	USD
CY2018	us-gaap	Share Based Compensation ShareBasedCompensation	424000000	USD
CY2020	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	132000000	USD
CY2019	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	92000000	USD
CY2018	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	81000000	USD
CY2020	tmus	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Adjustments ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdjustments	887528	shares
CY2020	tmus	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Performance Award Achievement Adjustments Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsPerformanceAwardAchievementAdjustmentsWeightedAverageGrantDateFairValue	70.96
CY2020	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	439000000	USD
CY2019	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	156000000	USD
CY2020Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Maximum Employee Subscription Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionRate	0.15
CY2020	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Discount From Market Price Purchase Date ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPricePurchaseDate	0.15
CY2020	tmus	Employee Stock Purchase Plan Offering Period EmployeeStockPurchasePlanOfferingPeriod	P6M
CY2020	tmus	Employee Stock Purchase Plans Number Of Securities Remaining For Future Sale And Issuance EmployeeStockPurchasePlansNumberOfSecuritiesRemainingForFutureSaleAndIssuance	4253858	shares
CY2020	tmus	Aggregate Number Of Shares Annual Increase Employee Stock Purchase Plans AggregateNumberOfSharesAnnualIncreaseEmployeeStockPurchasePlans	5000000	shares
CY2020Q1	tmus	Additional Shares Of Common Stock Employee Stock Purchase Plan AdditionalSharesOfCommonStockEmployeeStockPurchasePlan	5000000	shares
CY2020	tmus	Share Based Compensation Arrangement By Share Based Payment Award Incentive Compensation Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardIncentiveCompensationGrantDateFairValue	163000000	USD
CY2020	us-gaap	Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Expected Long Term Return On Assets DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets	0.05
CY2020	tmus	Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Actual Rate Of Return On Plan Assets During Period DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostActualRateOfReturnOnPlanAssetsDuringPeriod	0.21
CY2020	tmus	Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Expected Long Term Rate Of Return On Investments In Next Fiscal Year DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermRateOfReturnOnInvestmentsInNextFiscalYear	0.04
CY2020	us-gaap	Defined Benefit Plan Interest Cost DefinedBenefitPlanInterestCost	52000000	USD
CY2020	us-gaap	Defined Benefit Plan Expected Return On Plan Assets DefinedBenefitPlanExpectedReturnOnPlanAssets	45000000	USD
CY2020	us-gaap	Defined Benefit Plan Net Periodic Benefit Cost DefinedBenefitPlanNetPeriodicBenefitCost	7000000	USD
CY2020	tmus	Defined Benefit Plan Percent Of Portfolio Valued At Quoted Price DefinedBenefitPlanPercentOfPortfolioValuedAtQuotedPrice	0.12
CY2020	tmus	Defined Benefit Plan Percent Of Portfolio Valued Using Similar Assets In Active Or Inactive Markets DefinedBenefitPlanPercentOfPortfolioValuedUsingSimilarAssetsInActiveOrInactiveMarkets	0.85
CY2020	tmus	Defined Benefit Plan Percent Of Portfolio Valued Using Unobservable Inputs DefinedBenefitPlanPercentOfPortfolioValuedUsingUnobservableInputs	0.03
CY2020Q2	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	1200000000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	1400000000	USD
CY2020Q2	us-gaap	Defined Benefit Plan Benefit Obligation DefinedBenefitPlanBenefitObligation	2100000000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Benefit Obligation DefinedBenefitPlanBenefitObligation	2300000000	USD
CY2020Q2	us-gaap	Defined Benefit Plan Funded Status Of Plan DefinedBenefitPlanFundedStatusOfPlan	-892000000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Funded Status Of Plan DefinedBenefitPlanFundedStatusOfPlan	-828000000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Discount Rate DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate	0.03
CY2020	us-gaap	Defined Benefit Plan Contributions By Employer DefinedBenefitPlanContributionsByEmployer	58000000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Expected Future Employer Contributions Next Fiscal Year DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear	89000000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Next Twelve Months DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths	97000000	USD
CY2020Q4	tmus	Defined Benefit Plan Expected Future Benefit Payment Years Two And Three DefinedBenefitPlanExpectedFutureBenefitPaymentYearsTwoAndThree	198000000	USD
CY2020Q4	tmus	Defined Benefit Plan Expected Future Benefit Payment Years Four And Five DefinedBenefitPlanExpectedFutureBenefitPaymentYearsFourAndFive	-206000000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Five Fiscal Years Thereafter DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter	548000000	USD
CY2020	us-gaap	Defined Contribution Plan Employer Discretionary Contribution Amount DefinedContributionPlanEmployerDiscretionaryContributionAmount	179000000	USD
CY2019	us-gaap	Defined Contribution Plan Employer Discretionary Contribution Amount DefinedContributionPlanEmployerDiscretionaryContributionAmount	119000000	USD
CY2018	us-gaap	Defined Contribution Plan Employer Discretionary Contribution Amount DefinedContributionPlanEmployerDiscretionaryContributionAmount	102000000	USD
CY2020	us-gaap	Cash Provided By Used In Operating Activities Discontinued Operations CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations	611000000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	3493000000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	4557000000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	3686000000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	37000000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	46000000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	231000000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	3530000000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	4603000000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	3917000000	USD
CY2020	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	-17000000	USD
CY2019	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	-24000000	USD
CY2018	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	-39000000	USD
CY2020	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	84000000	USD
CY2019	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	70000000	USD
CY2018	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	63000000	USD
CY2020	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	10000000	USD
CY2019	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	-2000000	USD
CY2018	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	25000000	USD
CY2020	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	77000000	USD
CY2019	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	44000000	USD
CY2018	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	49000000	USD
CY2020	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	676000000	USD
CY2019	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	954000000	USD
CY2018	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	750000000	USD
CY2020	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	34000000	USD
CY2019	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	125000000	USD
CY2018	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	160000000	USD
CY2020	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	-1000000	USD
CY2019	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	12000000	USD
CY2018	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	70000000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	786000000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	1135000000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	1029000000	USD
CY2020	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
CY2019	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
CY2018	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Change In Enacted Tax Rate EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate	-0.008
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Change In Enacted Tax Rate EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate	0.004
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Change In Enacted Tax Rate EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate	0.019
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	-0.026
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	-0.018
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	-0.016
CY2020	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.048
CY2019	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.051
CY2018	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.048
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential	0.003
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential	0.003
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential	0.024
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense EffectiveIncomeTaxRateReconciliationNondeductibleExpense	0.004
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense EffectiveIncomeTaxRateReconciliationNondeductibleExpense	0.006
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense EffectiveIncomeTaxRateReconciliationNondeductibleExpense	0.007
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits EffectiveIncomeTaxRateReconciliationTaxCredits	0.009
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits EffectiveIncomeTaxRateReconciliationTaxCredits	0.008
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits EffectiveIncomeTaxRateReconciliationTaxCredits	0.029
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Share Based Compensation Cost EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost	0.025
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Share Based Compensation Cost EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost	0.006
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Share Based Compensation Cost EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost	0.008
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Other EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther	0.023
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Other EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther	0.006
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Other EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther	0.008
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0.003
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	-0.001
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0
CY2020	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.223
CY2019	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.247
CY2018	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.263
CY2020Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	4540000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	823000000	USD
CY2020Q4	tmus	Deferred Tax Assets Operating Lease Liability DeferredTaxAssetsOperatingLeaseLiability	8031000000	USD
CY2019Q4	tmus	Deferred Tax Assets Operating Lease Liability DeferredTaxAssetsOperatingLeaseLiability	3403000000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Property Plant And Equipment DeferredTaxAssetsPropertyPlantAndEquipment	90000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Property Plant And Equipment DeferredTaxAssetsPropertyPlantAndEquipment	0	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals	1348000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals	659000000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Credit Carryforwards DeferredTaxAssetsTaxCreditCarryforwards	411000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Credit Carryforwards DeferredTaxAssetsTaxCreditCarryforwards	331000000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	2665000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	903000000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	17085000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	6119000000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	878000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	129000000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	16207000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	5990000000	USD
CY2020Q4	tmus	Deferred Tax Liabilities Goodwilland Intangible Assets Indefinite Lived Intangible Assets DeferredTaxLiabilitiesGoodwillandIntangibleAssetsIndefiniteLivedIntangibleAssets	17518000000	USD
CY2019Q4	tmus	Deferred Tax Liabilities Goodwilland Intangible Assets Indefinite Lived Intangible Assets DeferredTaxLiabilitiesGoodwillandIntangibleAssetsIndefiniteLivedIntangibleAssets	5902000000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	0	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	2506000000	USD
CY2020Q4	tmus	Deferred Tax Liabilities Operating Lease Right Of Use Asset DeferredTaxLiabilitiesOperatingLeaseRightOfUseAsset	7239000000	USD
CY2019Q4	tmus	Deferred Tax Liabilities Operating Lease Right Of Use Asset DeferredTaxLiabilitiesOperatingLeaseRightOfUseAsset	2881000000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets	912000000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets	19000000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	504000000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	289000000	USD
CY2020Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	26173000000	USD
CY2019Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	11597000000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	9966000000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	5607000000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	9966000000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	5607000000	USD
CY2020Q4	tmus	Unrecognized Tax Benefits Indirect Tax Effects Excluded UnrecognizedTaxBenefitsIndirectTaxEffectsExcluded	144000000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	878000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	129000000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	210000000	USD
CY2019Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	514000000	USD
CY2018Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	462000000	USD
CY2017Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	412000000	USD
CY2020	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	6000000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	0	USD
CY2018	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	16000000	USD
CY2020	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	28000000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	0	USD
CY2019	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0
CY2018	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	11000000	USD
CY2020	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	45000000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	64000000	USD
CY2018	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	39000000	USD
CY2020	us-gaap	Unrecognized Tax Benefits Increases Resulting From Acquisition UnrecognizedTaxBenefitsIncreasesResultingFromAcquisition	624000000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Increases Resulting From Acquisition UnrecognizedTaxBenefitsIncreasesResultingFromAcquisition	0	USD
CY2018	us-gaap	Unrecognized Tax Benefits Increases Resulting From Acquisition UnrecognizedTaxBenefitsIncreasesResultingFromAcquisition	10000000	USD
CY2020	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	2000000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	12000000	USD
CY2018	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	4000000	USD
CY2020Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	1159000000	USD
CY2019Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	514000000	USD
CY2018Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	462000000	USD
CY2020Q4	us-gaap	Unrecognized Tax Benefits That Would Impact Effective Tax Rate UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate	857000000	USD
CY2019Q4	us-gaap	Unrecognized Tax Benefits That Would Impact Effective Tax Rate UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate	310000000	USD
CY2018Q4	us-gaap	Unrecognized Tax Benefits That Would Impact Effective Tax Rate UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate	263000000	USD
CY2018	us-gaap	Stock Repurchased And Retired During Period Shares StockRepurchasedAndRetiredDuringPeriodShares	16738758	shares
CY2018	tmus	Stock Repurchasedand Retired During Period Average Cost Per Share StockRepurchasedandRetiredDuringPeriodAverageCostPerShare	62.96
CY2018	us-gaap	Treasury Stock Value Acquired Par Value Method TreasuryStockValueAcquiredParValueMethod	1054000000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest	2744000000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest	3468000000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest	2888000000	USD
CY2020	us-gaap	Income Loss From Discontinued Operations Net Of Tax IncomeLossFromDiscontinuedOperationsNetOfTax	320000000	USD
CY2019	us-gaap	Income Loss From Discontinued Operations Net Of Tax IncomeLossFromDiscontinuedOperationsNetOfTax	0	USD
CY2018	us-gaap	Income Loss From Discontinued Operations Net Of Tax IncomeLossFromDiscontinuedOperationsNetOfTax	0	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	3064000000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	3468000000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	2888000000	USD
CY2020	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	1144206326	shares
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	854143751	shares
CY2018	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	849744152	shares
CY2020	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	10543102	shares
CY2019	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	9289760	shares
CY2018	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	8546022	shares
CY2020	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	1154749428	shares
CY2019	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	863433511	shares
CY2018	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	858290174	shares
CY2020	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	2.40
CY2019	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	4.06
CY2018	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	3.40
CY2020	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0.28
CY2019	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0
CY2018	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0
CY2020	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.68
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	4.06
CY2018	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.40
CY2020	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	2.37
CY2019	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	4.02
CY2018	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	3.36
CY2020	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0.28
CY2018	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0
CY2020	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.65
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	4.02
CY2018	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.36
CY2020Q2	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	2000000000	shares
CY2020	us-gaap	Operating Lease Expense OperatingLeaseExpense	4438000000	USD
CY2019	us-gaap	Operating Lease Expense OperatingLeaseExpense	2558000000	USD
CY2020	us-gaap	Finance Lease Right Of Use Asset Amortization FinanceLeaseRightOfUseAssetAmortization	681000000	USD
CY2019	us-gaap	Finance Lease Right Of Use Asset Amortization FinanceLeaseRightOfUseAssetAmortization	523000000	USD
CY2020	us-gaap	Finance Lease Interest Expense FinanceLeaseInterestExpense	81000000	USD
CY2019	us-gaap	Finance Lease Interest Expense FinanceLeaseInterestExpense	82000000	USD
CY2020	tmus	Finance Lease Expense FinanceLeaseExpense	762000000	USD
CY2019	tmus	Finance Lease Expense FinanceLeaseExpense	605000000	USD
CY2020	us-gaap	Variable Lease Cost VariableLeaseCost	328000000	USD
CY2019	us-gaap	Variable Lease Cost VariableLeaseCost	243000000	USD
CY2020	us-gaap	Lease Cost LeaseCost	5528000000	USD
CY2019	us-gaap	Lease Cost LeaseCost	3406000000	USD
CY2020Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P10Y
CY2019Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P6Y
CY2019Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P6Y
CY2020Q4	us-gaap	Finance Lease Weighted Average Remaining Lease Term1 FinanceLeaseWeightedAverageRemainingLeaseTerm1	P3Y
CY2019Q4	us-gaap	Finance Lease Weighted Average Remaining Lease Term1 FinanceLeaseWeightedAverageRemainingLeaseTerm1	P3Y
CY2019Q4	us-gaap	Finance Lease Weighted Average Remaining Lease Term1 FinanceLeaseWeightedAverageRemainingLeaseTerm1	P3Y
CY2020Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.039
CY2019Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.048
CY2020Q4	us-gaap	Finance Lease Weighted Average Discount Rate Percent FinanceLeaseWeightedAverageDiscountRatePercent	0.033
CY2019Q4	us-gaap	Finance Lease Weighted Average Discount Rate Percent FinanceLeaseWeightedAverageDiscountRatePercent	0.040
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due Next Rolling Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextRollingTwelveMonths	4903000000	USD
CY2020Q4	us-gaap	Finance Lease Liability Payments Due In Next Rolling Twelve Months FinanceLeaseLiabilityPaymentsDueInNextRollingTwelveMonths	1121000000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due In Rolling Year Two LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearTwo	4354000000	USD
CY2020Q4	us-gaap	Finance Lease Liability Payments Due In Rolling Year Two FinanceLeaseLiabilityPaymentsDueInRollingYearTwo	795000000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due In Rolling Year Three LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearThree	3759000000	USD
CY2020Q4	us-gaap	Finance Lease Liability Payments Due In Rolling Year Three FinanceLeaseLiabilityPaymentsDueInRollingYearThree	422000000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due In Rolling Year Four LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearFour	3339000000	USD
CY2020Q4	us-gaap	Finance Lease Liability Payments Due In Rolling Year Four FinanceLeaseLiabilityPaymentsDueInRollingYearFour	137000000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due In Rolling Year Five LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearFive	2807000000	USD
CY2020Q4	us-gaap	Finance Lease Liability Payments Due In Rolling Year Five FinanceLeaseLiabilityPaymentsDueInRollingYearFive	92000000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due After Rolling Year Five LesseeOperatingLeaseLiabilityPaymentsDueAfterRollingYearFive	18940000000	USD
CY2020Q4	us-gaap	Finance Lease Liability Payments Due In Rolling After Year Five FinanceLeaseLiabilityPaymentsDueInRollingAfterYearFive	61000000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	38102000000	USD
CY2020Q4	us-gaap	Finance Lease Liability Payments Due FinanceLeaseLiabilityPaymentsDue	2628000000	USD
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CY2020Q4	us-gaap	Finance Lease Liability Undiscounted Excess Amount FinanceLeaseLiabilityUndiscountedExcessAmount	121000000	USD
CY2020Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	30587000000	USD
CY2020Q4	us-gaap	Finance Lease Liability FinanceLeaseLiability	2507000000	USD
CY2020	us-gaap	Finance Lease Interest Payment On Liability FinanceLeaseInterestPaymentOnLiability	79000000	USD
CY2019	us-gaap	Finance Lease Interest Payment On Liability FinanceLeaseInterestPaymentOnLiability	82000000	USD
CY2020Q4	tmus	Lessee Operating Lease Lease Notyet Commenced Payments Due LesseeOperatingLeaseLeaseNotyetCommencedPaymentsDue	227000000	USD
CY2020Q4	us-gaap	Lessor Operating Lease Payments To Be Received Next Rolling Twelve Months LessorOperatingLeasePaymentsToBeReceivedNextRollingTwelveMonths	1687000000	USD
CY2020Q4	us-gaap	Lessor Operating Lease Payments To Be Received Rolling Year Two LessorOperatingLeasePaymentsToBeReceivedRollingYearTwo	92000000	USD
CY2020Q4	us-gaap	Lessor Operating Lease Payments To Be Received LessorOperatingLeasePaymentsToBeReceived	1779000000	USD
CY2020Q4	tmus	Purchase Obligation Due In Next Rolling Twelve Months PurchaseObligationDueInNextRollingTwelveMonths	5000000000.0	USD
CY2020Q4	tmus	Purchase Obligation Due In Rolling Year Two And Three PurchaseObligationDueInRollingYearTwoAndThree	4500000000	USD
CY2020Q4	tmus	Purchase Obligation Due In Rolling Year Four And Five PurchaseObligationDueInRollingYearFourAndFive	2400000000	USD
CY2020Q4	tmus	Purchase Obligation Due In Rolling After Year Five PurchaseObligationDueInRollingAfterYearFive	1700000000	USD
CY2020Q4	tmus	Lease And Service Credit Commitment Due In Next Rolling Twelve Months LeaseAndServiceCreditCommitmentDueInNextRollingTwelveMonths	338000000	USD
CY2020Q4	tmus	Lease And Service Credit Commitment Due In Rolling Year Two And Three LeaseAndServiceCreditCommitmentDueInRollingYearTwoAndThree	675000000	USD
CY2020Q4	tmus	Lease And Service Credit Commitment Due In Rolling Year Four And Five LeaseAndServiceCreditCommitmentDueInRollingYearFourAndFive	594000000	USD
CY2020Q4	tmus	Lease And Service Credit Commitment Due In Rolling After Year Five LeaseAndServiceCreditCommitmentDueInRollingAfterYearFive	5100000000	USD
CY2020Q4	tmus	Lease And Service Credit Commitment Maximum Remaining Commitment LeaseAndServiceCreditCommitmentMaximumRemainingCommitment	92000000	USD
CY2020Q4	tmus	Merger Commitment Settlement Due In Next Rolling Twelve Months MergerCommitmentSettlementDueInNextRollingTwelveMonths	23000000	USD
CY2020Q4	tmus	Merger Commitment Settlement Due In Rolling Year Two And Three MergerCommitmentSettlementDueInRollingYearTwoAndThree	37000000	USD
CY2020Q4	tmus	Merger Commitment Settlement Due In Rolling Year Four And Five MergerCommitmentSettlementDueInRollingYearFourAndFive	13000000	USD
CY2020	us-gaap	Restructuring Charges RestructuringCharges	1060000000	USD
CY2020	us-gaap	Operating Lease Right Of Use Asset Amortization Expense OperatingLeaseRightOfUseAssetAmortizationExpense	153000000	USD
CY2020Q2	us-gaap	Restructuring Reserve RestructuringReserve	0	USD
	us-gaap	Restructuring Charges RestructuringCharges	1060000000	USD
	us-gaap	Payments For Restructuring PaymentsForRestructuring	738000000	USD
	us-gaap	Restructuring Reserve Accrual Adjustment1 RestructuringReserveAccrualAdjustment1	-159000000	USD
CY2020Q4	us-gaap	Restructuring Reserve RestructuringReserve	163000000	USD
CY2020	tmus	Restructuring Term RestructuringTerm	P3Y
CY2020Q4	us-gaap	Accounts Payable Trade Current AccountsPayableTradeCurrent	5564000000	USD
CY2019Q4	us-gaap	Accounts Payable Trade Current AccountsPayableTradeCurrent	4322000000	USD
CY2020Q4	us-gaap	Accrual For Taxes Other Than Income Taxes Current AccrualForTaxesOtherThanIncomeTaxesCurrent	1163000000	USD
CY2019Q4	us-gaap	Accrual For Taxes Other Than Income Taxes Current AccrualForTaxesOtherThanIncomeTaxesCurrent	802000000	USD
CY2020Q4	us-gaap	Employee Related Liabilities Current EmployeeRelatedLiabilitiesCurrent	1540000000	USD
CY2019Q4	us-gaap	Employee Related Liabilities Current EmployeeRelatedLiabilitiesCurrent	682000000	USD
CY2020Q4	us-gaap	Interest Payable Current InterestPayableCurrent	771000000	USD
CY2019Q4	us-gaap	Interest Payable Current InterestPayableCurrent	227000000	USD
CY2020Q4	us-gaap	Accrued Sales Commission Current AccruedSalesCommissionCurrent	399000000	USD
CY2019Q4	us-gaap	Accrued Sales Commission Current AccruedSalesCommissionCurrent	251000000	USD
CY2020Q4	tmus	Accrued Liabilities Toll And Interconnect AccruedLiabilitiesTollAndInterconnect	217000000	USD
CY2019Q4	tmus	Accrued Liabilities Toll And Interconnect AccruedLiabilitiesTollAndInterconnect	156000000	USD
CY2020Q4	us-gaap	Accrued Advertising Current AccruedAdvertisingCurrent	135000000	USD
CY2019Q4	us-gaap	Accrued Advertising Current AccruedAdvertisingCurrent	127000000	USD
CY2020Q4	us-gaap	Other Accrued Liabilities Current OtherAccruedLiabilitiesCurrent	407000000	USD
CY2019Q4	us-gaap	Other Accrued Liabilities Current OtherAccruedLiabilitiesCurrent	179000000	USD
CY2020Q4	us-gaap	Accounts Payable And Accrued Liabilities Current AccountsPayableAndAccruedLiabilitiesCurrent	10196000000	USD
CY2019Q4	us-gaap	Accounts Payable And Accrued Liabilities Current AccountsPayableAndAccruedLiabilitiesCurrent	6746000000	USD
CY2020	us-gaap	Interest Paid Net InterestPaidNet	2733000000	USD
CY2019	us-gaap	Interest Paid Net InterestPaidNet	1128000000	USD
CY2018	us-gaap	Interest Paid Net InterestPaidNet	1525000000	USD
CY2020	us-gaap	Operating Lease Payments OperatingLeasePayments	4619000000	USD
CY2019	us-gaap	Operating Lease Payments OperatingLeasePayments	2783000000	USD
CY2018	us-gaap	Operating Lease Payments OperatingLeasePayments	0	USD
CY2020	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	218000000	USD
CY2019	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	88000000	USD
CY2018	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	51000000	USD
CY2020	us-gaap	Consideration Received For Beneficial Interest Obtained For Transferring Financial Asset ConsiderationReceivedForBeneficialInterestObtainedForTransferringFinancialAsset	6194000000	USD
CY2019	us-gaap	Consideration Received For Beneficial Interest Obtained For Transferring Financial Asset ConsiderationReceivedForBeneficialInterestObtainedForTransferringFinancialAsset	6509000000	USD
CY2018	us-gaap	Consideration Received For Beneficial Interest Obtained For Transferring Financial Asset ConsiderationReceivedForBeneficialInterestObtainedForTransferringFinancialAsset	4972000000	USD
CY2020	tmus	Noncash Or Part Noncash Acquisition Consideration NoncashOrPartNoncashAcquisitionConsideration	33533000000	USD
CY2019	tmus	Noncash Or Part Noncash Acquisition Consideration NoncashOrPartNoncashAcquisitionConsideration	0	USD
CY2018	tmus	Noncash Or Part Noncash Acquisition Consideration NoncashOrPartNoncashAcquisitionConsideration	0	USD
CY2020	tmus	Change In Capital Expenditures Incurred But Not Yet Paid ChangeInCapitalExpendituresIncurredButNotYetPaid	-589000000	USD
CY2019	tmus	Change In Capital Expenditures Incurred But Not Yet Paid ChangeInCapitalExpendituresIncurredButNotYetPaid	935000000	USD
CY2018	tmus	Change In Capital Expenditures Incurred But Not Yet Paid ChangeInCapitalExpendituresIncurredButNotYetPaid	-65000000	USD
CY2020	us-gaap	Noncash Or Part Noncash Acquisition Fixed Assets Acquired1 NoncashOrPartNoncashAcquisitionFixedAssetsAcquired1	2795000000	USD
CY2019	us-gaap	Noncash Or Part Noncash Acquisition Fixed Assets Acquired1 NoncashOrPartNoncashAcquisitionFixedAssetsAcquired1	1006000000	USD
CY2018	us-gaap	Noncash Or Part Noncash Acquisition Fixed Assets Acquired1 NoncashOrPartNoncashAcquisitionFixedAssetsAcquired1	1011000000	USD
CY2020	us-gaap	Noncash Or Part Noncash Acquisition Inventory Acquired1 NoncashOrPartNoncashAcquisitionInventoryAcquired1	1460000000	USD
CY2019	us-gaap	Noncash Or Part Noncash Acquisition Inventory Acquired1 NoncashOrPartNoncashAcquisitionInventoryAcquired1	267000000	USD
CY2018	us-gaap	Noncash Or Part Noncash Acquisition Inventory Acquired1 NoncashOrPartNoncashAcquisitionInventoryAcquired1	326000000	USD
CY2020	us-gaap	Noncash Or Part Noncash Acquisition Debt Assumed1 NoncashOrPartNoncashAcquisitionDebtAssumed1	38000000	USD
CY2019	us-gaap	Noncash Or Part Noncash Acquisition Debt Assumed1 NoncashOrPartNoncashAcquisitionDebtAssumed1	800000000	USD
CY2018	us-gaap	Noncash Or Part Noncash Acquisition Debt Assumed1 NoncashOrPartNoncashAcquisitionDebtAssumed1	291000000	USD
CY2020	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	14129000000	USD
CY2019	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	3621000000	USD
CY2018	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	0	USD
CY2020	us-gaap	Right Of Use Asset Obtained In Exchange For Finance Lease Liability RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability	1273000000	USD
CY2019	us-gaap	Right Of Use Asset Obtained In Exchange For Finance Lease Liability RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability	1041000000	USD
CY2018	us-gaap	Right Of Use Asset Obtained In Exchange For Finance Lease Liability RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability	885000000	USD
CY2020Q1	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	11113000000	USD
CY2020Q2	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	17671000000	USD
CY2020Q3	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	19272000000	USD
CY2020Q4	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	20341000000	USD
CY2020	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	68397000000	USD
CY2020Q1	us-gaap	Operating Income Loss OperatingIncomeLoss	1539000000	USD
CY2020Q2	us-gaap	Operating Income Loss OperatingIncomeLoss	820000000	USD
CY2020Q3	us-gaap	Operating Income Loss OperatingIncomeLoss	2565000000	USD
CY2020Q4	us-gaap	Operating Income Loss OperatingIncomeLoss	1712000000	USD
CY2020	us-gaap	Operating Income Loss OperatingIncomeLoss	6636000000	USD
CY2020Q1	us-gaap	Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest	951000000	USD
CY2020Q2	us-gaap	Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest	-210000000	USD
CY2020Q3	us-gaap	Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest	1253000000	USD
CY2020Q4	us-gaap	Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest	750000000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest	2744000000	USD
CY2020Q1	us-gaap	Income Loss From Discontinued Operations Net Of Tax IncomeLossFromDiscontinuedOperationsNetOfTax	0	USD
CY2020Q2	us-gaap	Income Loss From Discontinued Operations Net Of Tax IncomeLossFromDiscontinuedOperationsNetOfTax	320000000	USD
CY2020Q3	us-gaap	Income Loss From Discontinued Operations Net Of Tax IncomeLossFromDiscontinuedOperationsNetOfTax	0	USD
CY2020Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.10
CY2020Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.09
CY2020Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.00
CY2020Q4	us-gaap	Income Loss From Discontinued Operations Net Of Tax IncomeLossFromDiscontinuedOperationsNetOfTax	0	USD
CY2020	us-gaap	Income Loss From Discontinued Operations Net Of Tax IncomeLossFromDiscontinuedOperationsNetOfTax	320000000	USD
CY2020Q1	us-gaap	Net Income Loss NetIncomeLoss	951000000	USD
CY2020Q2	us-gaap	Net Income Loss NetIncomeLoss	110000000	USD
CY2020Q3	us-gaap	Net Income Loss NetIncomeLoss	1253000000	USD
CY2020Q4	us-gaap	Net Income Loss NetIncomeLoss	750000000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	3064000000	USD
CY2020Q1	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	1.11
CY2020Q2	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	-0.17
CY2020Q3	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	1.01
CY2020Q4	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	0.60
CY2020	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	2.40
CY2020Q1	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0
CY2020Q2	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0.26
CY2020Q3	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0
CY2020Q4	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0
CY2020	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0.28
CY2020Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.11
CY2020Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.09
CY2020Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.01
CY2020Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.60
CY2020	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.68
CY2020Q1	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	1.10
CY2020Q2	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	-0.17
CY2020Q3	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	1.00
CY2020Q4	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	0.60
CY2020	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	2.37
CY2020Q1	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0
CY2020Q2	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0.26
CY2020Q3	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0
CY2020Q4	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0
CY2020	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0.28
CY2020Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.60
CY2019Q1	us-gaap	Operating Income Loss OperatingIncomeLoss	1476000000	USD
CY2020	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.65
CY2020Q1	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	858148284	shares
CY2020Q2	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	1236528444	shares
CY2020Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	1238450665	shares
CY2020Q4	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	1241578615	shares
CY2020	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	1144206326	shares
CY2020Q1	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	865998532	shares
CY2020Q2	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	1236528444	shares
CY2020Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	1249798740	shares
CY2020Q4	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	1251566899	shares
CY2020	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	1154749428	shares
CY2019Q1	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	11080000000	USD
CY2019Q2	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	10979000000	USD
CY2019Q3	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	11061000000	USD
CY2019Q4	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	11878000000	USD
CY2019	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	44998000000	USD
CY2019Q2	us-gaap	Operating Income Loss OperatingIncomeLoss	1541000000	USD
CY2019Q3	us-gaap	Operating Income Loss OperatingIncomeLoss	1471000000	USD
CY2019Q4	us-gaap	Operating Income Loss OperatingIncomeLoss	1234000000	USD
CY2019	us-gaap	Operating Income Loss OperatingIncomeLoss	5722000000	USD
CY2019Q1	us-gaap	Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest	908000000	USD
CY2019Q2	us-gaap	Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest	939000000	USD
CY2019Q3	us-gaap	Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest	870000000	USD
CY2019Q4	us-gaap	Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest	751000000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest	3468000000	USD
CY2019Q1	us-gaap	Net Income Loss NetIncomeLoss	908000000	USD
CY2019Q2	us-gaap	Net Income Loss NetIncomeLoss	939000000	USD
CY2019Q3	us-gaap	Net Income Loss NetIncomeLoss	870000000	USD
CY2019Q4	us-gaap	Net Income Loss NetIncomeLoss	751000000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	3468000000	USD
CY2019Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.07
CY2019Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.10
CY2019Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.02
CY2019Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.88
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	4.06
CY2019Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.06
CY2019Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.09
CY2019Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.01
CY2019Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.87
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	4.02
CY2019Q1	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	851223498	shares
CY2019Q2	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	854368443	shares
CY2019Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	854578241	shares
CY2019Q4	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	856294467	shares
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	854143751	shares
CY2019Q1	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	858643481	shares
CY2019Q2	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	860135593	shares
CY2019Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	862690751	shares
CY2019Q4	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	864158739	shares
CY2019	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	863433511	shares

Files In Submission

Name	View Source	Status
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$TMUS
T-Mobile US, Inc. Stock $tmus

2020 Q4 Form 10-K Financial Statement

#000128369921000039 Filed on February 23, 2021

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$TMUS T-Mobile US, Inc. Stock $tmus

2020 Q4 Form 10-K Financial Statement

#000128369921000039 Filed on February 23, 2021

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$TMUS
T-Mobile US, Inc. Stock $tmus