Purchased Patents (Tables)

9 Months Ended

Sep. 30, 2012

Purchased Patents

Schedule of gross carrying amount and related accumulated amortization of the patents

			December 31, 2010				December 31, 2011				September 30, 2012
	Weighted- Average Life		Gross Carrying Amount		Accumulated Amortization		Gross Carrying Amount		Accumulated Amortization		Gross Carrying Amount		Accumulated Amortization
											(unaudited)
			(in thousands)
Purchased patents		10.0	$	2,292	$	1,150	$	2,292	$	1,380	$	2,292	$	1,552