Business Segment, Product, and Geographic Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014 segment	Sep. 30, 2013
Segment Reporting [Abstract]
Number of Reportable Segments			1
Revenue from spine surgery product line offerings
Total revenues	$ 189,918	$ 169,156	$ 558,090	$ 494,358
Spine Surgery Products [Member]
Revenue from spine surgery product line offerings
Total revenues	146,739	131,137	431,379	382,485
Biologics [Member]
Revenue from spine surgery product line offerings
Total revenues	32,632	28,743	94,958	83,754
Monitoring Service [Member]
Revenue from spine surgery product line offerings
Total revenues	$ 10,547	$ 9,276	$ 31,753	$ 28,119