Application of Recent Accounting Pronouncements (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Maximum exposure to loss in relation to the activities of the VIEs	$ 33,484	$ 38,504
Separate account assets	$ (27,775,827)	(26,631,193)
Accounting Standards Update 2015-02 | Adjustments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Maximum exposure to loss in relation to the activities of the VIEs		35,776
Fair Value, Inputs, Level 2 | Accounting Standards Update 2015-07 | Adjustments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Separate account assets		$ 533,961