Business segment information (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Market sector information
Total Net Sales	$ 119,492	$ 116,670	$ 235,534	$ 229,731
Reported Growth (as a percent)	2.00%		3.00%
Constant Currency Growth (as a percent)	5.00%		4.00%
Spine
Market sector information
Total Net Sales	81,795	76,542	156,823	149,117
Reported Growth (as a percent)	7.00%		5.00%
Constant Currency Growth (as a percent)	7.00%		5.00%
Spine Repair Implants and Regenerative Biologics
Market sector information
Total Net Sales	38,501	36,882	74,258	70,839
Reported Growth (as a percent)	4.00%		5.00%
Constant Currency Growth (as a percent)	4.00%		5.00%
Spine Regenerative Stimulation
Market sector information
Total Net Sales	43,294	39,660	82,565	78,278
Reported Growth (as a percent)	9.00%		5.00%
Constant Currency Growth (as a percent)	9.00%		5.00%
Orthopedics
Market sector information
Total Net Sales	$ 37,697	$ 40,128	$ 78,711	$ 80,614
Reported Growth (as a percent)	(6.00%)		(2.00%)
Constant Currency Growth (as a percent)	2.00%		3.00%