CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
Net gain from curtailment, tax			$ 11,384
Net actuarial gain (loss), tax	$ (4,798)	$ (8,639)	11,892
Pension settlement expense, tax	1,246	2,565	821
Amortization of unrecognized net periodic benefit costs, tax	1,571	979	3,014
Change in unrealized loss on interest rate swap, tax	(126)	(226)
Change in foreign currency translation, tax	$ (451)	$ (137)	$ (79)