Certain Nontraditional Long-Duration Contracts (Changes in Deferred Sales Inducements, Reported as "Interest credited to policyholders' account balances") (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
DeferredSalesInducementsAbstract      
Beginning Balance $ 787,891 $ 542,742 $ 537,943
Capitalization 20,871 198,955 289,642
Amortization - Impact of assumption and experience unlocking and true-ups 14,613 53,108 (24,919)
Amortization - All other 160,835 (9,985) (260,964)
Change in unrealized investment gains and losses 5,679 3,071 1,040
Ending Balance $ 989,889 $ 787,891 $ 542,742