Deferred Acquisition Costs and Value of Business Acquired (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
DAC
Balance at the beginning of the period	$ 393,418	$ 353,408	$ 314,071
Capitalized additions	93,222	63,093	110,315
Amortization and writedowns	(29,317)	(96,095)	(41,045)
Unrealized investment (gains) losses	10,522	73,012	(29,933)
Balance at the end of the period	467,845	393,418	353,408
VOBA
Balance at the beginning of the period	20,725	25,286	29,217
Amortization and writedowns	(1,992)	(4,493)	(3,801)
Unrealized investment (gains) losses	112	(68)	(130)
Balance at the end of the period	18,845	20,725	25,286
Total
Balance at the beginning of the period	414,143	378,694	343,288
Capitalized additions	93,222	63,093	110,315
Amortization and writedowns	(31,309)	(100,588)	(44,846)
Unrealized investment (gains) losses	10,634	72,944	(30,063)
Balance at the end of the period	486,690	$ 414,143	$ 378,694
Estimated future amortization of VOBA
Estimated future amortization of VOBA in 2017	3,200
Estimated future amortization of VOBA in 2018	3,200
Estimated future amortization of VOBA in 2019	3,200
Estimated future amortization of VOBA in 2020	3,200
Estimated future amortization of VOBA in 2021	$ 3,200