Purchased Patents (Tables)

12 Months Ended

Dec. 31, 2012

Purchased Patents

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

The following sets forth the gross carrying amount and related accumulated amortization of the patents, in thousands:

			December 31, 2011				December 31, 2012
	Weighted- Average Life		Gross Carrying Amount		Accumulated Amortization		Gross Carrying Amount		Accumulated Amortization
Purchased patents		10.0	$	2,292	$	1,380	$	2,292	$	1,609