Condensed Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Condensed Consolidated Statements of Comprehensive Income
Net income	$ 74,228		$ 50,993
Components of other comprehensive income (loss)
Unrealized gains (losses) arising on fixed maturities, available-for-sale	(40,618)	[1]	34,110	[1]
Net change during the period related to cash flow hedges	23,948		(4,546)
Reclassification adjustment for (gains) losses realized in net income	(21,687)		(17,391)
Net unrealized gains (losses) related to investments	(38,357)		12,173
Future policy benefits, deferred acquisition costs and value of business acquired adjustments	14,687		12,151
Other comprehensive income (loss) before income taxes	(23,670)		24,324
Income tax (benefit) expense related to items of other comprehensive income (loss)	(8,285)		8,513
Other comprehensive income (loss)	(15,385)		15,811
Total comprehensive income	$ 58,843		$ 66,804

[1] Other comprehensive income (loss) includes the non-credit component of impaired losses on fixed maturities available-for-sale in the amounts of $3,726 and $5,718 for the three months ended March 31, 2013 and 2012, respectively.