CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
OPERATING ACTIVITIES:
Net income	$ 6,394	$ 13,419
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	19,717	18,253
Deferred income tax	7	(120)
Amortization of debt issuance costs	393	616
Non-cash interest expense	0	2,064
Loss on disposal of property and equipment	348	61
Change in fair value of contingent consideration and other	261	131
Share-based compensation	5,363	3,265
Changes in assets and liabilities, net of business acquisitions:
Accounts receivable	(589)	(18,440)
Inventories	(5,207)	(8,104)
Prepaid expenses and other current assets	(1,988)	1,288
Other non-current assets	(321)	(601)
Accounts payable, accrued expenses and other current liabilities	8,938	12,057
Deferred revenue	1,251	1,527
Other non-current liabilities	(5,685)	(386)
Net cash provided by operating activities	28,882	25,030
INVESTING ACTIVITIES:
Purchases of property and equipment	(9,191)	(10,895)
Cash used in business acquisition, net of cash acquired	(193,928)	0
Change in restricted cash	0	4,165
Proceeds from sale of short-term investments	9,976	0
Net cash used in investing activities	(193,143)	(6,730)
FINANCING ACTIVITIES:
Borrowings under senior credit facility	210,000	15,000
Repayments under senior credit facility	(20,000)	(1,875)
Principal payments under capital lease obligations	0	(160)
Proceeds from exercised stock options	1,167	1,038
Cash taxes paid in net equity settlement	(6,128)	(4,051)
Net cash provided by financing activities	185,039	9,952
Effect of exchange rate changes on cash and cash equivalents	1,280	702
Net increase in cash and cash equivalents	22,058	28,954
Cash and cash equivalents at beginning of period	102,055	48,132
Cash and cash equivalents at end of period	$ 124,113	$ 77,086