Reclassifications out of Accumulated Other Comprehensive Loss (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Equity [Abstract]
Amortization of prior service cost	$ (322)	$ (353)	$ (351)
Recognized net actuarial losses	13,875	6,764	1,503
Total reclassifications	13,553	6,411	1,152
Tax benefit	5,066	2,469	411
Total reclassifications, net of tax	$ 8,487	$ 3,942	$ 741