CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net income		$ 1,314	$ 131	$ 914
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization		533	506	468
Non cash impairment and restructuring costs		24	1,000	0
Non-cash interest expense, net of amortization of premium		21	20	17
Change in fair value of contingent consideration		(17)	0	0
Provision for doubtful accounts		53	60	53
Amortization of deferred income related to equity method investment		0	(3)	(3)
Loss on extinguishment of debt		83	40	57
Loss on unconsolidated entity investments, net		18	16	21
Dividend received from unconsolidated entity investment		2	2	2
Gain on other investments		(5)	(3)	(3)
Share-based payment expense		202	223	250
Deferred income tax expense		131	238	259
Amortization of right-of-use assets		50	56	56
Changes in operating assets and liabilities:
Receivables		(108)	(36)	(137)
Related party, net		7	0	(10)
Prepaid expenses and other current assets		(47)	12	21
Other long-term assets		(8)	(61)	7
Accounts payable and accrued expenses		104	42	109
Accrued interest		(1)	13	32
Deferred revenue		(287)	(223)	(58)
Operating lease liabilities		(55)	(53)	(47)
Other long-term liabilities		(16)	38	9
Net cash provided by operating activities		1,998	2,018	2,017
Cash flows from investing activities:
Additions to property and equipment		(388)	(350)	(363)
Proceeds from insurance recoveries		225	0	0
Purchases of other investments		(4)	(8)	(7)
Acquisition of business, net of cash acquired		(14)	(300)	313
Sale of short-term investments		0	0	73
Investments in related parties and other equity investees		(21)	(94)	(19)
Repayment from related party		2	11	0
Net cash used in investing activities		(200)	(741)	(3)
Cash flows from financing activities:
Proceeds from exercise of stock options		10	0	8
Taxes paid from net share settlements for stock-based compensation		(103)	(114)	(150)
Revolving credit facility, net		(653)	649	(439)
Proceeds from long-term borrowings, net of costs		4,442	1,481	2,715
Proceeds from sale of capped call security		0	0	3
Principal payments of long-term borrowings		(3,503)	(1,507)	(1,666)
Payment of premiums on redemption of debt		(62)	(31)	(45)
Payment of contingent consideration for business acquisition		(22)	0	0
Common stock repurchased and retired		(1,523)	(1,555)	(2,159)
Dividends paid		(268)	(237)	(226)
Net cash used in financing activities		(1,682)	(1,314)	(1,959)
Net increase (decrease) in cash, cash equivalents and restricted cash		116	(37)	55
Cash, cash equivalents and restricted cash at beginning of period	[1]	83	120	65
Cash, cash equivalents and restricted cash at end of period	[1]	199	83	120
Cash paid during the period for:
Interest, net of amounts capitalized		393	358	337
Income taxes paid		82	38	10
Non-cash investing and financing activities:
Treasury stock not yet settled		11	(19)	0
Fair value of shares issued related to acquisition of a business		0	0	2,355
Accumulated other comprehensive income, net of tax		$ 0	$ 7	$ 14

[1] The following table reconciles cash, cash equivalents and restricted cash per the statement of cash flows to the balance sheet. The restricted cash balances are primarily due to letters of credit which have been issued to the landlords of leased office space. The terms of the letters of credit primarily extend beyond one year. (in millions)December 31, 2021December 31, 2020December 31, 2019December 31, 2018Cash and cash equivalents$191 $71 $106 $54 Restricted cash included in Other long-term assets8 12 14 11 Total cash, cash equivalents and restricted cash at end of period$199 $83 $120 $65