Reinsurance - Summary of Reinsurance Activity (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Gross Amount
Premiums written and contract deposits, Gross Amount	$ 316,123	$ 316,798	$ 617,635	$ 604,790
Premiums and contract charges earned, Gross Amount	200,351	193,396	400,806	383,629
Benefits, claims and settlement expenses, Gross Amount	168,218	151,998	315,489	283,238
Ceded to Other Companies
Premiums written and contract deposits, Ceded to Other Companies	5,643	5,921	11,153	11,689
Premiums and contract charges earned, Ceded to Other Companies	5,665	5,952	11,199	11,721
Benefits, claims and settlement expenses, Ceded to Other Companies	3,185	4,444	7,068	17,106
Assumed from Other Companies
Premiums written and contract deposits, Assumed from Other Companies	1,134	1,002	1,864	1,947
Premiums and contract charges earned, Assumed from Other Companies	1,032	916	1,833	1,902
Benefits, claims and settlement expenses, Assumed from Other Companies	846	854	1,554	1,789
Net Amount
Premiums written and contract deposits, Net Amount	311,614	311,879	608,346	595,048
Premiums and contract charges earned, Net Amount	195,718	188,360	391,440	373,810
Benefits, claims and settlement expenses, Net Amount	$ 165,879	$ 148,408	$ 309,975	$ 267,921