Patent Assets, Net (Tables)

12 Months Ended

Dec. 31, 2014

Patent Assets [Abstract]

Patent Assets, Net

Patent assets, net consisted of the following (in thousands):

	December 31, 2013			Additions			Sales			December 31, 2014
Patent assets	$	529,526		$	136,468		$	(704	)	$	665,290
Accumulated amortization	(309,572		)	(119,694		)	325			(428,941		)
Patent assets, net	$	219,954								$	236,349

	December 31, 2012			Additions			Sales			December 31, 2013
Patent assets	$	403,875		$	126,501		$	(850	)	$	529,526
Accumulated amortization	(204,561		)	(105,533		)	522			(309,572		)
Patent assets, net	$	199,314								$	219,954

Expected Future Annual Amortization Of Patent Assets

s of December 31, 2014, the Company expects amortization expense in future periods to be as follows (in thousands):

2015	$	111,415
2016	80,576
2017	36,241
2018	7,166
2019	951
Total estimated future amortization expense	$	236,349