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
Net income	$ 12,089	$ 10,990	$ 34,809		$ 26,673
Investments available-for-sale:
Net change in unrealized gains (losses) on investments available-for-sale	(1,032)	2,594	(24,925)		3,943
Related income tax (expense) benefit	407	(1,035)	9,935		(1,573)
Net investment gains reclassified into earnings	0	296	118		459
Related income tax expense	0	(118)	(47)		(183)
Net effect on other comprehensive income (loss) for the period	(625)	1,737	(14,919)		2,646
Defined benefit pension plan:
Recognition of unrealized gain	249	197	1,176	[1]	896	[1]
Related income tax expense	(91)	(78)	(461)		(357)
Net effect on other comprehensive income for the period	158	119	715		539
Total other comprehensive income (loss)	(467)	1,856	(14,204)		3,185
Comprehensive income	$ 11,622	$ 12,846	$ 20,605		$ 29,858

[1] This amount is included in the computation of net periodic benefit cost, see Note 10