CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating Activities
Net income	$ 162,546	$ 342,660	$ 247,644
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	414,621	413,344	400,871
Amortization of upfront incentive consideration	82,935	77,622	67,411
Stock-based compensation expense	66,885	57,263	44,689
Deferred income taxes	(22,925)	43,099	48,760
Allowance for doubtful accounts	20,563	7,749	9,459
Amortization of debt issuance costs	3,972	3,981	5,923
Joint venture equity income	(2,044)	(2,556)	(2,580)
Loss (income) from discontinued operations	1,766	(1,739)	1,932
Dividends received from joint venture investments	1,352	1,411	1,088
Tax Receivable Agreement	0	4,852	(59,603)
Debt modification costs	0	1,558	14,758
Loss on extinguishment of debt	0	633	1,012
Impairment and related charges	0	0	81,112
Other	2,777	(2,349)	13,284
Changes in operating assets and liabilities:
Accounts and other receivables	(33,911)	(45,586)	(108,596)
Prepaid expenses and other current assets	1,145	14,362	109
Capitalized implementation costs	(28,588)	(39,168)	(60,766)
Upfront incentive consideration	(71,447)	(88,735)	(94,296)
Other assets	38,795	(29,607)	(21,111)
Accounts payable and other accrued liabilities	(27,232)	(27,080)	67,034
Accrued compensation and related benefits	(17,469)	(15,044)	6,038
Deferred revenue including upfront solution fees	(12,481)	8,127	13,861
Cash provided by operating activities	581,260	724,797	678,033
Investing Activities
Additions to property and equipment	(115,166)	(283,940)	(316,436)
Acquisitions, net of cash acquired	(107,462)	0	0
Other investing activities	(20,398)	8,681	(1,089)
Cash used in investing activities	(243,026)	(275,259)	(317,525)
Financing Activities
Cash dividends paid to common stockholders	(153,508)	(154,080)	(154,861)
Payments on borrowings from lenders	(106,560)	(47,310)	(1,880,506)
Payments on Tax Receivable Agreement	(101,482)	(58,908)	(99,241)
Repurchase of common stock	(77,636)	(26,281)	(109,100)
Proceeds of borrowings from lenders	45,000	0	1,897,625
Net (payments) receipts on the settlement of equity-based awards	(5,736)	2,040	12,647
Debt issuance and modification costs	0	(1,567)	(19,052)
Other financing activities	(9,799)	(20,400)	(4,292)
Cash used in financing activities	(409,721)	(306,506)	(356,780)
Cash Flows from Discontinued Operations
Cash used in operating activities	(2,383)	(1,895)	(4,848)
Cash used in discontinued operations	(2,383)	(1,895)	(4,848)
Effect of exchange rate changes on cash and cash equivalents	781	6,747	(1,613)
(Decrease) increase in cash and cash equivalents	(73,089)	147,884	(2,733)
Cash and cash equivalents at beginning of period	509,265	361,381	364,114
Cash and cash equivalents at end of period	436,176	509,265	361,381
Cash payments for income taxes	55,137	57,629	40,211
Cash payments for interest	157,648	156,041	149,572
Capitalized interest	5,085	8,823	11,142
Non-cash additions to property and equipment	$ 33,136	$ 0	$ 0