Application of Recent Accounting Pronouncements Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Maximum loss exposure of VIE	$ 38,504	$ 32,444
Separate account assets	26,631,193	$ 27,037,765
Accounting Standards Update 2015-02 | Restatement Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Maximum loss exposure of VIE	35,776
Accounting Standards Update 2015-07 | Significant other observable inputs (Level 2) | Restatement Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Separate account assets	(533,961)
Removal of investments	286
Accounting Standards Update 2015-07 | Significant unobservable inputs (Level 3) | Restatement Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Removal of investments	$ 7,654