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Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Amount, after accumulated amortization, of debt discount (premium).

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Long-term Debt and Finance Leases - Schedule of Long-term Debt and Finance Leases (Details) $ / shares in Units, $ in Millions		12 Months Ended
	Jan. 29, 2021 $ / shares	Dec. 31, 2020 USD ($) $ / shares	Dec. 31, 2019 USD ($) $ / shares	Dec. 02, 2020	Mar. 11, 2020	May 28, 2019	May 24, 2019	May 14, 2019	Dec. 07, 2017	Aug. 02, 2016	May 23, 2016
Debt Instrument [Line Items]
Long-term debt		$ 8,855	$ 6,042
Finance leases		4	0
Subtotal long-term debt and finance leases (including current maturities)		8,859	6,042
Less current maturities		(1)	(88)
Less debt issuance costs		(93)	(65)
Discounts		(74)	(86)
Total long-term debt and finance leases		8,691	5,803
Debt Instrument, Unamortized Discount [Abstract]
Total discounts		(74)	(86)
Recourse Debt
Debt Instrument [Line Items]
Long-term debt		8,855	6,008
Recourse Debt \| Senior Notes, due 2026
Debt Instrument [Line Items]
Long-term debt		$ 1,000	1,000
Interest rate, stated percentage		7.25%									7.25%
Recourse Debt \| Senior Notes, due 2027
Debt Instrument [Line Items]
Long-term debt		$ 1,230	1,230
Interest rate, stated percentage		6.625%								6.625%
Recourse Debt \| Senior Notes, due 2028
Debt Instrument [Line Items]
Long-term debt		$ 821	821
Interest rate, stated percentage		5.75%							5.75%
Recourse Debt \| Senior Notes, due 2029
Debt Instrument [Line Items]
Long-term debt		$ 733	733
Interest rate, stated percentage		5.25%					5.25%	5.25%
Recourse Debt \| Senior Notes, due 2029
Debt Instrument [Line Items]
Long-term debt		$ 500	0
Interest rate, stated percentage		3.375%		3.375%
Recourse Debt \| 3.625% Senior Unsecured Notes Due 2031 [Member]
Debt Instrument [Line Items]
Long-term debt		$ 1,030	0
Interest rate, stated percentage		3.625%		3.625%
Recourse Debt \| Convertible Senior Notes Due 2048
Debt Instrument [Line Items]
Long-term debt		$ 575	575
Discounts		$ (72)	$ (85)
Interest rate, stated percentage		2.75%
Effective rate		5.19%	5.05%
Conversion price per common share (in usd per share) \| $ / shares		$ 46.24	$ 47.74
Conversion ratio		0.0216242	0.0209479
Debt Instrument, Unamortized Discount [Abstract]
Total discounts		$ (72)	$ (85)
Recourse Debt \| Convertible Senior Notes Due 2048 \| Subsequent Event
Debt Instrument [Line Items]
Conversion price per common share (in usd per share) \| $ / shares	$ 45.94
Conversion ratio	0.02177
Debt discount amortization period	4 years 8 months 12 days
Recourse Debt \| Senior Secured First Lien Notes, due 2024
Debt Instrument [Line Items]
Long-term debt		$ 600	600
Interest rate, stated percentage		3.75%				2.75%
Recourse Debt \| Senior Secured First Lien Notes, due 2025
Debt Instrument [Line Items]
Long-term debt		$ 500	0
Interest rate, stated percentage		2.00%		2.00%
Recourse Debt \| Senior Secured First Lien Notes, due 2027
Debt Instrument [Line Items]
Long-term debt		$ 900	0
Interest rate, stated percentage		2.45%		2.45%
Recourse Debt \| Senior Secured First Lien Notes, due 2029
Debt Instrument [Line Items]
Long-term debt		$ 500	500
Interest rate, stated percentage		4.45%				4.45%
Recourse Debt \| Tax-exempt bonds
Debt Instrument [Line Items]
Long-term debt		$ 466	466
Recourse Debt \| Tax-exempt bonds \| Minimum
Debt Instrument [Line Items]
Interest rate, stated percentage		1.25%			1.30%
Recourse Debt \| Tax-exempt bonds \| Maximum
Debt Instrument [Line Items]
Interest rate, stated percentage		4.75%
Recourse Debt \| Senior Secured First Lien Notes, due 2024, 2025, 2027 and 2029
Debt Instrument [Line Items]
Discounts		$ (2)	(1)
Debt Instrument, Unamortized Discount [Abstract]
Total discounts		(2)	(1)
Line of Credit \| Revolving Credit Facility \| Revolving Credit Facility
Debt Instrument [Line Items]
Long-term debt		$ 0	83
Line of Credit \| Revolving Credit Facility \| Revolving Credit Facility \| LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)		1.75%
Non Recourse Debt
Debt Instrument [Line Items]
Long-term debt		$ 0	34
Non Recourse Debt \| Other
Debt Instrument [Line Items]
Long-term debt		$ 0	$ 34