CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
OPERATING ACTIVITIES:
Net income	$ 35,663	$ 20,388
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	83,053	62,281
Non-cash impairment charges	4,941	3,290
Deferred income tax	789	(935)
Amortization of debt issuance costs	4,953	1,178
Realized loss on sale of short-term investment	0	2,287
Loss on disposal of property and equipment	969	443
Change in fair value of contingent consideration and other	1,214	(2,773)
Share-based compensation	15,786	16,359
Changes in assets and liabilities, net of business acquisitions:
Accounts receivable	1,180	(9,861)
Inventories	(3,441)	(862)
Prepaid expenses and other current assets	3,432	(14,691)
Other non-current assets	(1,397)	(1,977)
Accounts payable, accrued expenses and other current liabilities	9,418	24,021
Deferred revenue	(111)	1,405
Other non-current liabilities	546	2,442
Net cash provided by operating activities	156,995	102,995
INVESTING ACTIVITIES:
Purchases of property and equipment	(52,056)	(29,806)
Proceeds from sale of short-term investments	0	16,951
Proceeds from note receivable	679	483
Proceeds from sale of property and equipment	298	157
Cash provided by business acquisitions	26,704
Cash used in business acquisitions		(225,552)
Net cash used in investing activities	(24,375)	(237,767)
FINANCING ACTIVITIES:
Borrowings under senior credit facility	50,000	571,383
Repayments under senior credit facility	(460,000)	(65,000)
Payment of debt issuance costs	(4,388)	0
Proceeds from the issuance of common stock, net of issuance costs	349,590	0
Net cash paid for financing liabilities from business acquisitions	(33,843)	(4,661)
Proceeds from exercised stock options	9,239	9,774
Cash taxes paid in net equity settlement	(7,415)	(6,763)
Net cash (used in) provided by financing activities	(96,817)	504,733
Effect of exchange rate changes on cash and cash equivalents	(4,747)	9,927
Net increase in cash and cash equivalents	31,056	379,888
Cash and cash equivalents at beginning of period	174,935	102,055
Cash and cash equivalents at end of period	$ 205,991	$ 481,943