Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Net income	$ 13,010	$ 9,854	$ 25,224	$ 19,360
Other comprehensive income, before tax:
Change in net unrealized gain (losses) during period	(1,864)	21,000	(1,107)	21,419
Reclassification adjustment for net gains included in income	(198)	(16)	(229)	(18)
Defined benefit post-retirement benefits plans:
Change in net actuarial loss	35	35	68	69
Other comprehensive income, before tax	(2,027)	21,019	(1,268)	21,470
Deferred tax benefit (expense) related to other comprehensive income	797	(8,271)	499	(8,448)
Other comprehensive income (loss), net of tax	(1,230)	12,748	(769)	13,022
Comprehensive income, net of tax	$ 11,780	$ 22,602	$ 24,455	$ 32,382