Employee Benefit Plans (Details 3) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Reclassifications related to the SERP from accumulated other comprehensive loss to the statement of operations
Prior service cost	$ 1,234	$ 1,234
Amortization of net actuarial loss	160	210
Total prior service cost and amortization of net actuarial loss	1,394	1,444
Tax benefit	(517)	(540)
Total, net of tax	877	904
Research and development
Reclassifications related to the SERP from accumulated other comprehensive loss to the statement of operations
Prior service cost	408	408
Amortization of net actuarial loss		69
Selling, general and administrative
Reclassifications related to the SERP from accumulated other comprehensive loss to the statement of operations
Prior service cost	826	826
Amortization of net actuarial loss	$ 160	$ 141