CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Cash Flows from Operating Activities:
Net income	$ 60,861	$ 19,728
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	6,718	8,954
Non-cash compensation	7,811	8,230
401(k) employer match	4,894	4,367
Loss on disposal of property and equipment	650	147
Deferred income taxes	9,145	7,582
Equity in earnings from equity method investments	(4,836)	(2,249)
Amortization of deferred debt issuance costs	355	370
Write off of deferred debt issuance costs	38	0
Return on equity investment	2,204	3,416
Changes in operating assets and liabilities, net of impact of acquisitions:
Patient accounts receivable	3,604	(6,833)
Other current assets	(11,680)	(6,892)
Other assets	688	(1,148)
Accounts payable	3,623	1,093
Securities Class Action Lawsuit settlement accrual, net	0	28,712
Accrued expenses	4,548	(2,743)
Other long-term obligations	2,347	607
Net cash provided by operating activities	90,970	63,341
Cash Flows from Investing Activities:
Proceeds from sale of deferred compensation plan assets	471	565
Proceeds from the sale of property and equipment	11	0
Purchase of investment	0	(436)
Purchases of property and equipment	(1,611)	(7,449)
Acquisitions of businesses, net of cash acquired	(4,074)	(24,128)
Net cash used in investing activities	(5,203)	(31,448)
Cash Flows from Financing Activities:
Proceeds from issuance of stock upon exercise of stock options and warrants	2,609	4,203
Proceeds from issuance of stock to employee stock purchase plan	1,157	1,187
Shares withheld upon stock vesting	(2,832)	(5,726)
Non-controlling interest distribution	(350)	(90)
Proceeds from borrowings under revolving line of credit	127,500	0
Principal payments of long-term obligations	(90,475)	(2,500)
Debt issuance costs	(2,433)	0
Purchase of company stock	(181,402)	0
Net cash used in financing activities	(146,226)	(2,926)
Net (decrease) increase in cash and cash equivalents	(60,459)	28,967
Cash and cash equivalents at beginning of period	86,363	30,197
Cash and cash equivalents at end of period	25,904	59,164
Supplemental Disclosures of Cash Flow Information:
Cash paid for interest	2,080	1,172
Cash paid for income taxes, net of refunds received	$ 6,149	$ 284