Patents (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Patents [Line Items]
Patents, weighted average useful life	7 years
Payments to acquire intangible assets	$ 178,260,000	$ 14,680,000	$ 8,224,000
Accrued patent acquisition related payments	0	900,000
Accelerated amortization expense	10,574,000	3,111,000	1,171,000
Accelerated amortization expense (termination)	2,823,000	821,000	275,000
Patent cost, disposals	5,500,000	4,612,000	1,540,000
Accumulated amortization, disposals	2,466,000	3,509,000	1,108,000
Proceeds from patent sale	3,347,000	11,000,000	240,000
Patent cost, sale	$ 0	$ 4,717,000	$ 94,000
Minimum [Member]
Patents [Line Items]
Patents, useful life	1 year
Acquired Finite Lived Intangible Asset, Useful Life	1 year
Maximum [Member]
Patents [Line Items]
Patents, useful life	10 years
Acquired Finite Lived Intangible Asset, Useful Life	8 years
Patents [Member] | Minimum [Member]
Patents [Line Items]
Patents, useful life	1 year
Patents [Member] | Maximum [Member]
Patents [Line Items]
Patents, useful life	9 years