CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
OPERATING ACTIVITIES:
Net income	$ 13,382	$ 7,031
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	31,159	29,164
Non-cash impairment charges	409	600
Deferred income tax	1,648	(503)
Amortization of debt issuance costs	1,060	1,243
Non-cash interest expense	3,744	3,433
Loss on disposal of property and equipment	38	378
Change in fair value of contingent consideration	239	(998)
Share-based compensation	5,616	8,302
Excess tax benefits from stock-based compensation arrangements	(3,501)	(1,164)
Changes in assets and liabilities, net of business acquisitions:
Accounts receivable	(4,480)	106
Inventories	(9,875)	(17,367)
Prepaid expenses and other current assets	(7,314)	(2,832)
Other non-current assets	(1,806)	(1,846)
Accounts payable, accrued expenses and other current liabilities	19,613	4,848
Deferred revenue	(805)	188
Other non-current liabilities	615	(2,952)
Net cash provided by operating activities	49,742	27,631
INVESTING ACTIVITIES:
Purchases of property and equipment	(22,013)	(20,691)
Sale of property and equipment	1,438	0
Cash used in business acquisition, net of cash acquired	0	(235,000)
Proceeds from working capital purchase price adjustment	1,831	0
Net cash used in investing activities	(18,744)	(255,691)
FINANCING ACTIVITIES:
Borrowings under senior credit facility	35,000	235,000
Repayments under senior credit facility	(15,000)	0
Principal payments under capital lease obligations	(396)	(245)
Proceeds from exercised stock options	7,345	8,317
Excess tax benefits from stock-based compensation arrangements	3,501	1,164
Net cash provided by financing activities	30,450	244,236
Effect of exchange rate changes on cash and cash equivalents	(2,146)	370
Net change in cash and cash equivalents	59,302	16,546
Cash and cash equivalents at beginning of period	71,994	120,614
Cash and cash equivalents at end of period	$ 131,296	$ 137,160