Consolidated Statements of Comprehensive Income (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income Statement [Abstract]
Tax provision on defined benefit pension plans	$ 21	$ (12)	$ 37	$ 76
Tax provision on loss on derivative instrument classified as a cash flow hedge	$ 718	$ (12)	$ 2,926	$ (134)