Business Segment, Product, and Geographic Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014 segment	Jun. 30, 2013
Segment Reporting [Abstract]
Number of Reportable Segments			1
Revenue from spine surgery product line offerings
Total revenues	$ 190,677	$ 165,698	$ 368,172	$ 325,202
Spine Surgery Products [Member]
Revenue from spine surgery product line offerings
Total revenues	147,333	128,682	284,640	251,348
Biologics [Member]
Revenue from spine surgery product line offerings
Total revenues	32,837	27,855	62,327	55,012
Monitoring Service [Member]
Revenue from spine surgery product line offerings
Total revenues	$ 10,507	$ 9,161	$ 21,205	$ 18,842