Summary of Investments SOI Other-than-temporary impairment recognition (Details) - Total fixed maturity investments - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Beginning balance	$ 102,343	$ 119,532	$ 167,961
Initial impairments - credit loss on securities not previously impaired	0	759	0
Due to sales, maturities, or payoffs during the period	(1,785)	(559)	(646)
Due to increases in cash flows expected to be collected that are recognized over the remaining life of the security	(16,893)	(17,389)	(47,783)
Ending balance	$ 83,665	$ 102,343	$ 119,532