GOODWILL AND OTHER INTANGIBLE ASSETS - Schedule of Changes in Carrying Amount of Goodwill (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014		Dec. 31, 2013
Goodwill [Line Items]
Goodwill, gross			$ 296,502
Accumulated impairment losses			(46,738)
Goodwill [Roll Forward]
Goodwill at December 31, 2013	249,764	[1]
Goodwill acquired during period	105,331
Foreign currency translation	(5,521)
Goodwill at September 30, 2014	349,574
U.S. Neurosurgery
Goodwill [Line Items]
Goodwill, gross			95,165
Accumulated impairment losses			0
Goodwill [Roll Forward]
Goodwill at December 31, 2013	95,165
Goodwill acquired during period	95,373
Foreign currency translation	(2,966)
Goodwill at September 30, 2014	187,572
U.S. Instruments
Goodwill [Line Items]
Goodwill, gross			58,033
Accumulated impairment losses			0
Goodwill [Roll Forward]
Goodwill at December 31, 2013	58,033
Goodwill acquired during period	0
Foreign currency translation	(901)
Goodwill at September 30, 2014	57,132
U.S. Extremities
Goodwill [Line Items]
Goodwill, gross			61,079
Accumulated impairment losses			0
Goodwill [Roll Forward]
Goodwill at December 31, 2013	61,079
Goodwill acquired during period	0
Foreign currency translation	(948)
Goodwill at September 30, 2014	60,131
U.S. Spine And Other [Member]
Goodwill [Line Items]
Goodwill, gross			56,325
Accumulated impairment losses			(46,738)
Goodwill [Roll Forward]
Goodwill at December 31, 2013	9,587
Goodwill acquired during period	0
Foreign currency translation	(149)
Goodwill at September 30, 2014	9,438
International
Goodwill [Line Items]
Goodwill, gross			25,900
Accumulated impairment losses			0
Goodwill [Roll Forward]
Goodwill at December 31, 2013	25,900
Goodwill acquired during period	9,958
Foreign currency translation	(557)
Goodwill at September 30, 2014	$ 35,301

[1] See Note 1 of these condensed consolidated financial statements for discussion of the impact of the change in accounting for the medical device excise tax.