Certain Nontraditional Long-Duration Contracts (Changes in Deferred Sales Inducements, Reported as "Interest credited to policyholders' account (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011		Dec. 31, 2010
deferredsalesinducements
Deferred Sales Inducements, Beginning Balance	$ 445,841	$ 796,507		$ 801,876
deferredsalesinducementsadditions	59,269	68,370		182,823
Amortization - Impact of assumption and experience unlocking and true-ups	133,214	(56,736)		32,445
Amortization - All other	(94,752)	(378,682)		(232,542)
Change in unrealized investment gains and losses	13,258	147		11,905
Deferred Sales Inducements, Ending Balance	556,830	445,841		796,507
OtherChangesToDeferredSalesInducements		$ 16,235	[1]

[1] Balance sheet reclassification between DAC and DSI relating to refinement in methodology for allocating DAC/DSI balances for cohorts with both DAC and DSI persistency credits. Refer to Note 4 for impact to DAC.