Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash flows from operating activities:
Net loss	$ (732,192)	$ (1,507,033)
Loss from discontinued operations	718,125	1,539,314
Adjustments to reconcile net income to net cash from operating activities:
Depreciation and amortization	20,749	18,830
Amortization of premiums, discounts and issuance costs	4,076	4,293
Stock-based compensation expense	36,120	27,512
Deferred income taxes	30,214	(13,484)
Other	(30)	3,370
Changes in assets and liabilities:
Accounts receivable	30,006	7,491
Prepaid expenses and other current assets	(1,716)	(22,545)
Other long-term assets	7,703	21,825
Accounts payable and accrued expenses	(36,433)	(2,238)
Income taxes payable / receivable	(28,837)	(25,838)
Long-term professional liabilities	15,703	4,508
Other liabilities	8,157	(19,768)
Net cash provided by operating activities – continuing operations	71,645	36,237
Net cash provided by operating activities—discontinued operations	144,841	186,177
Net cash provided by operating activities	216,486	222,414
Cash flows from investing activities:
Acquisition payments, net of cash acquired	(2,225)	(31,200)
Purchases of investments	(36,090)	(13,907)
Proceeds from maturities or sales of investments	30,865	26,240
Purchases of property and equipment	(21,809)	(14,862)
Proceeds from sale of business, net of cash sold	1,080	0
Net cash used in investing activities – continuing operations	(28,179)	(33,729)
Net cash provided by (used in) investing activities—discontinued operations	3,079	(20,793)
Net cash used in investing activities	(25,100)	(54,522)
Cash flows from financing activities:
Borrowings on credit agreement	527,500	1,225,800
Payments on credit agreement	(527,500)	(1,755,500)
Proceeds from issuance of senior notes	0	500,000
Payments for credit facility amendment and financing costs	(510)	(9,194)
Payments on finance lease obligations	(433)	0
Proceeds from issuance of common stock	5,697	9,157
Contribution from noncontrolling interests	245	0
Repurchases of common stock	(8,495)	(144,925)
Net cash used in financing activities – continuing operations	(3,496)	(174,662)
Net cash used in financing activities—discontinued operations	(1,248)	(8,909)
Net cash used in financing activities	(4,744)	(183,571)
Net increase (decrease) in cash and cash equivalents	186,642	(15,679)
Cash and cash equivalents at beginning of period	107,870	40,774
Cash and cash equivalents at end of period	$ 294,512	$ 25,095