CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
OPERATING ACTIVITIES:
Net income (loss)	$ 74,564	$ (3,519)	$ 34,004
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Loss from discontinued operations, net of tax	0	10,370	2,291
Depreciation and amortization	72,665	58,863	46,434
Non-cash impairment charges	0	380	790
Deferred income tax provision (benefit)	(6,474)	(351)	(6,849)
Non-cash valuation allowance	0	37,210	0
Share-based compensation	17,310	15,450	14,554
Amortization of debt issuance costs	2,529	2,264	2,571
Non-cash interest expense	8,074	7,911	7,104
Loss on disposal of property and equipment	1,765	481	909
Change in fair value of contingent consideration and others	(13)	(177)	(764)
Gain on bargain purchase	0	(1,111)	0
Payment of accreted interest	(42,786)	(384)	0
Changes in assets and liabilities, net of business acquisitions:
Accounts receivable	(17,518)	(16,231)	(17,145)
Inventories	(9,576)	(3,759)	(24,138)
Prepaid expenses and other current assets	14,912	(233)	16,526
Other non-current assets	(475)	610	(10,914)
Accounts payable, accrued expenses and other current liabilities	(414)	8,208	811
Deferred revenue	1,251	136	1,118
Other non-current liabilities	591	945	(4,357)
Net cash provided by operating activities of continuing operations	116,405	117,063	62,945
Net cash (used in) provided by operating activities of discontinued operations	0	(12,209)	20,620
Net cash provided by operating activities	116,405	104,854	83,565
INVESTING ACTIVITIES:
Change in restricted cash	4,165	(4,087)	0
Cash used in business acquisitions, net of cash acquired	225	(328,888)	(320,921)
Purchases of property and equipment	(47,328)	(33,413)	(38,340)
Sales of property and equipment	316	1,438	0
Other changes in intangible assets	0	0	(475)
Net cash used in investing activities of continuing operations	(42,622)	(364,950)	(359,736)
Net cash used in investing activities of discontinued operations	0	(7,060)	(3,581)
Net cash used in investing activities	(42,622)	(372,010)	(363,317)
FINANCING ACTIVITIES:
Borrowings under senior credit facility	680,000	545,000	425,000
Repayments under senior credit facility	(511,250)	(465,625)	(195,000)
Proceeds from the issuance of common stock, net of issuance costs	0	219,669	0
Distribution to SeaSpine	0	(47,013)	0
Payment of liability component of convertible notes	(184,313)	(2,519)	0
Payment of capital lease obligation	(653)	(709)	(605)
Debt issuance costs	(4,530)	(1,426)	(3,210)
Proceeds from exercised stock options	10,481	7,345	15,215
Cash taxes paid in net equity settlement	(4,851)	(6,580)	(2,718)
Net cash (used in) provided by financing activities	(15,116)	248,142	238,682
Effect of exchange rate changes on cash and cash equivalents	(4,744)	(4,848)	(7,550)
Net increase (decrease) in cash and cash equivalents	53,923	(23,862)	(48,620)
Cash and cash equivalents at beginning of period	48,132	71,994	120,614
Cash and cash equivalents at end of period	$ 102,055	$ 48,132	$ 71,994