Statutory Requirements (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($) member	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Statutory Accounting Practices [Line Items]
Liquidity ratio, minimum percentage required	75.00%
Bermuda
Statutory Accounting Practices [Line Items]
Actual statutory capital and surplus	$ 1,044,340	$ 1,296,067
Required statutory capital and surplus	612,620	622,624
Statutory net income	(68,188)	56,686	$ 229,974
Statutory amount available for dividend payments without regulatory approval	261,100	326,100
United States
Statutory Accounting Practices [Line Items]
Actual statutory capital and surplus	250,993	0
Required statutory capital and surplus	84,858	$ 0
Statutory net income	$ (7,510)
Statutory maximum percentage available for dividend payments	25.00%
Dividend payments with regulatory approval, number of members required | member	2
Minimum Net Capital Required for Entity	$ 250,000
Statutory amount available for dividend payments without regulatory approval	$ 11,100