CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Statement of Other Comprehensive Income [Abstract]
Net income	$ 4,190	$ 15,333	$ 4,410	$ 14,628
Other comprehensive income (loss), net of tax:
Net unrealized losses on available-for-sale investments	(786)	0	(1,677)	0
Defined benefit pension items:
Net gain (loss) arising during the period	87	(338)	2,100	(338)
Settlement cost included in net periodic cost	212	147	606	147
Amortization of loss included in net periodic cost	50	5	248	5
Amortization of prior service cost included in net periodic cost	0	110	0	328
Total other comprehensive income (loss), net of tax	(437)	(76)	1,277	142
Total comprehensive income	$ 3,753	$ 15,257	$ 5,687	$ 14,770