Leadership Changes and Restructuring Activities - Rollforward of Estimated Fair Value Liability Established for Total Severance and Other Related Costs (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Restructuring Cost and Reserve [Line Items]
Balance, January 1, 2015			$ 2,021
Severance and other related expenses			1,043
Accretion			48
Cash payments			(1,565)
Non-cash adjustment	$ (501)	$ (430)	(1,812)	$ (1,098)
Balance, September 30, 2015	$ 1,216		1,216
Separation And Transition Agreement
Restructuring Cost and Reserve [Line Items]
Non-cash adjustment			$ (331)