9. Sources of Other Comprehensive Income (Details) (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 unrealized investment gains	$ 17,789	$ 11,871	$ 25,382	$ 15,122
Other comprehensive income	17,789	11,871	25,382	15,122
Gross
Unrealized gains on investments	45,313	17,908	65,132	31,398
Adjustments for net realized investment (gains) losses on available-for-sale securities included in net income	499	(900)	1,099	(712)
Net unrealized investment gains	45,812	17,008	66,231	30,686
Net unrealized gains (losses) on derivative instruments	0	0	0	0
Other comprehensive income	45,812	17,008	66,231	30,686
Applicable deferred policy acquisition cost amortization	18,445	11,436	27,183	16,113
Applicable deferred income tax expense (benefit)	9,578	(6,299)	13,666	(549)
Offsets to other comprehensive income	28,023	5,137	40,849	15,564
Other comprehensive income	17,789	11,871	25,382	15,122
Net
Unrealized gains on investments	16,781	12,441	24,597	15,574
Adjustments for net realized investment (gains) losses on available-for-sale securities included in net income	1,008	(570)	785	(452)
Net unrealized investment gains	17,789	11,871	25,382	15,122
Net unrealized gains (losses) on derivative instruments	0	0	0	0
Other comprehensive income	$ 17,789	$ 11,871	$ 25,382	$ 15,122