CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (unaudited) (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]
Net income	$ 10,322	$ 9,424	$ 14,336	$ 12,357
Other comprehensive income (loss), net of tax:
Net actuarial pension loss amortization, net of income tax of $0, $196, $0 and $589	0	310	0	929
Prior service cost (credit) amortization, net of income tax of $151, $151, $452 and $453	(238)	(238)	(714)	(714)
Other comprehensive income (loss), net of tax	(238)	72	(714)	215
Comprehensive income	$ 10,084	$ 9,496	$ 13,622	$ 12,572