CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
OPERATING ACTIVITIES:
Net income	$ 62,492	$ 22,368
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	53,985	54,002
Non-cash impairment charges	5,764	0
Deferred income tax	(9,077)	(423)
Amortization of debt issuance costs	2,713	3,657
Loss on disposal of property and equipment	611	127
Change in fair value of contingent consideration and other	10	914
Share-based compensation	9,859	10,214
Changes in assets and liabilities, net of business acquisitions:
Accounts receivable	(30,356)	(8,420)
Inventories	(21,558)	(3,596)
Prepaid expenses and other current assets	(14,806)	(1,959)
Other non-current assets	2,846	(436)
Accounts payable, accrued expenses and other current liabilities	16,410	(3,405)
Contract liabilities	(1,971)	(91)
Other non-current liabilities	1,086	4,792
Net cash provided by operating activities	78,008	77,744
INVESTING ACTIVITIES:
Purchases of property and equipment	(33,750)	(35,387)
Proceeds from note receivable	495	446
Proceeds from sale of property and equipment	35	205
Cash provided by business acquisitions	0	26,704
Net cash used in investing activities	(33,220)	(8,032)
FINANCING ACTIVITIES:
Proceeds from borrowings of long-term indebtedness	101,200	50,000
Payments on debt	(105,000)	(415,000)
Payment of debt issuance costs	0	(4,221)
Proceeds from the issuance of common stock, net of issuance costs	0	349,599
Net cash paid for financing liabilities from business acquisitions	0	(33,843)
Proceeds from exercised stock options	2,213	3,727
Cash taxes paid in net equity settlement	(6,212)	(7,240)
Net cash used in financing activities	(7,799)	(56,978)
Effect of exchange rate changes on cash and cash equivalents	257	(3,898)
Net increase in cash and cash equivalents	37,246	8,836
Cash and cash equivalents at beginning of period	138,838	174,935
Cash and cash equivalents at end of period	$ 176,084	$ 183,771