Consolidated Statements of Comprehensive Income (Unaudited) (Parenthetical) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Income Statement [Abstract]
Tax provision on defined benefit pension plans	$ 12	$ 25	$ 37	$ 76
Tax provision on loss on derivative instrument classified as a cash flow hedge	$ (2,139)	$ (2)	$ (2,148)	$ 75