CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (DEFICIT) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Stockholders' Equity [Abstract]
Change in fair value of derivative instruments, tax benefit	$ 54	$ 41	$ 21
Reclassified to statement of operations related to hedging activities, tax benefit (expense)		139	37,017
Pension liability adjustment, tax benefit (expense)	$ 394	$ 16,073	$ 29,474