CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
Net actuarial loss, tax expense (benefit)	$ (64)	$ (1,229)	$ (999)	$ (3,459)
Pension settlement expense, tax	290	219	1,051	569
Amortization of unrecognized net periodic benefit costs, tax	352	477	753	914
Change in unrealized income (loss) on interest rate swap, tax expense (benefit)	52	(93)	140	(446)
Change in foreign currency translation, tax expense (benefit)	$ (134)	$ (86)	$ (58)	$ 285