Condensed Consolidated Statements of Comprehensive Income/(Loss) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income/(loss)	$ (23,855)	$ 18,568
Other comprehensive income/(loss), net of taxes:
Interest rate swaps (net of $0.2 million and $0.1 million tax expense, respectively)	362	124
Qualified pension and post-employment benefit plans (net of $1.8 million and $19.2 million tax benefit, respectively)	2,610	(36,500)
Total other comprehensive income/(loss)	2,972	(36,376)
Comprehensive loss	$ (20,883)	$ (17,808)