CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
Net actuarial loss, tax expense (benefit)	$ 899	$ (935)
Pension settlement expense, tax	168	761
Amortization of unrecognized net periodic benefit costs, tax	219	401
Change in unrealized income (loss) on interest rate swap, tax expense (benefit)	219	88
Change in foreign currency translation, tax expense (benefit)	$ (223)	$ 76