Restructuring Expense - Other Restructuring Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Restructuring activities
Restructuring expenses	$ 1,524	$ 1,826	$ 2,128	$ (3,272)	$ 4,164	$ 40,843	$ (270)	$ 6,188	$ 2,206	$ 50,925	$ 40,521
Other Restructuring
Restructuring activities
Liability, beginning of the period				$ 869				$ 8,441	869	8,441	0
Cash payments									(3,374)	(10,570)	(22,916)
Asset impairments and other non-cash expense									0	0	(7,594)
Restructuring expenses									3,955	2,998	38,951
Liability, end of the period	$ 1,450				$ 869				$ 1,450	$ 869	$ 8,441