Segment And Geographic Information (Revenues By Market Category) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Segment Reporting Information [Line Items]
Total revenue, net	$ 203,523	$ 202,185	$ 193,329	$ 181,041	$ 194,134	$ 186,641	$ 178,595	$ 172,698	$ 780,078	$ 732,068	$ 682,487
Orthopedics [Member]
Segment Reporting Information [Line Items]
Total revenue, net									328,782	290,050	262,170
Neurosurgery [Member]
Segment Reporting Information [Line Items]
Total revenue, net									285,341	275,046	256,544
Instruments [Member]
Segment Reporting Information [Line Items]
Total revenue, net									$ 165,955	$ 166,972	$ 163,773