Condensed Consolidated Statements of Comprehensive Income (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
Statement of Comprehensive Income [Abstract]
Tax benefit (expense) on actuarial loss, employee benefit plans	$ (1,731)	$ (25)	$ 1,919	$ 1,686
Tax expense, adjustment for items reclassified to earnings, employee benefit plans	$ 528	$ 404	$ 1,391	$ 1,206