Minimum Guarantees - Separate Account Liabilities for GMDB (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Net Amount at Risk by Product and Guarantee [Line Items]
Separate account liability	$ 266,239	$ 60,388
Net amount at risk, net of reinsurance	36,632	30,095
GMDB
Net Amount at Risk by Product and Guarantee [Line Items]
Separate account liability	55,999	60,388
Net amount at risk, net of reinsurance	$ 29,050	$ 30,095
Weighted average attained age	70 years	69 years
GLWB
Net Amount at Risk by Product and Guarantee [Line Items]
Separate account liability	$ 210,240	$ 0
Net amount at risk, net of reinsurance	$ 7,582	$ 0
Weighted average attained age	57 years