Condensed Consolidated Statements of Comprehensive Income - Unaudited (Parenthetical) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net loss arising from period, tax	$ 0	$ 0	$ (119)	$ 0
Amortization of prior service cost included in net periodic pension cost, tax	0	0	28	0
Partial settlement of pension plan liability, tax	0	0	336	0
Unrealized gains (losses) on change in fair value of interest rate swap contracts, tax	199	37	549	27
Reclassification adjustment for (gains) losses included in net income, tax	$ (101)	$ (49)	$ (280)	$ (101)