Supplemental Cash Flow Information (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	Dec. 31, 2020
Supplemental Cash Flow Information [Line Items]
Cash payments related to operating lease liabilities	[1]	$ 139	$ 137
Interest Paid		225	259
Income Taxes Paid		0	0
New ROU assets obtained in exchange for operating lease liabilities		140	132
Increase (decrease) in accounts payable for purchases of property and equipment		(8)	(18)
Purchase of property and equipment under capital leases and installment purchases		1	4
Reconciliation of cash, cash equivalents and restricted cash [Line Items]
Cash and cash equivalents		312		$ 292
Restricted cash, current		165		169
Restricted Cash, Noncurrent		5		5
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents		$ 482	$ 438	$ 466	$ 381

[1] Excludes the Company's contingent payments pursuant to operating leases, which are recorded as expense in the period such contingencies are resolved.