Goodwill and Other Identifiable Intangible Assets (Details) (USD $)	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011
Finite-Lived Intangible Assets [Line Items]
Patents, accumulated amortization	$ 41,457,000		$ (36,331,000)
For the remainder of 2012	15,176,000
2013	20,056,000
2014	19,802,000
2015	19,341,000
2016	18,236,000
Patent acquisition costs	(2,100,000)	(680,000)
Accrued patent acquisition related payments		875,000
Accelerated amortization expense	$ 442,000	$ 2,383,000