Schedule III - Supplementary Insurance Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Supplementary Insurance Information [Abstract]
Deferred policy acquisition costs	$ 2,905,377	$ 2,905,136	$ 2,058,556
Future policy benefits, losses, claims and loss expenses	51,637,026	45,495,431	39,802,861
Unearned premiums	0	0	0
Other policy claims and benefits payable	298,347	324,850	365,819
Premium revenue	217,346	172,216	151,613
Net investment income	1,849,872	1,692,192	1,531,667
Benefits, claims, losses and settlement expenses	1,572,586	758,203	1,679,255
Amortization of deferred policy acquisition costs	374,012	286,114	163,578
Other operating expenses	$ 143,437	$ 137,306	$ 130,076