Statutory Insurance Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statutory Accounting Practices [Line Items]
Statutory Accounting Practices, Statutory Amount Available for Dividend Payments	$ 98,500
Parent Company
Statutory Accounting Practices [Line Items]
Statutory accounting practices, net gain from operations	98,529	$ 100,819	$ 106,062
Statutory Accounting Practices, Statutory Net Income Amount	100,141	103,923	104,947
Statutory Accounting Practices, Statutory Capital and Surplus, Balance	642,409	637,205
Dividend Payments Restrictions Schedule, Statutory Capital and Surplus	508,926	503,722
Statutory RBC Total adjusted capital	718,175	704,541
Statutory Accounting Practices, Statutory Capital and Surplus Required	$ 127,864	$ 127,632
Statutory RBC Ratio	562.00%	552.00%
Subsidiaries
Statutory Accounting Practices [Line Items]
Statutory accounting practices, net gain from operations	$ 146	$ (321)	(192)
Statutory Accounting Practices, Statutory Net Income Amount	146	(321)	(192)
Statutory Accounting Practices, Statutory Capital and Surplus, Balance	8,814	8,677
Dividend Payments Restrictions Schedule, Statutory Capital and Surplus	(1,986)	(2,123)
Statutory RBC Total adjusted capital	8,826	8,688
Statutory Accounting Practices, Statutory Capital and Surplus Required	$ 194	$ 218
Statutory RBC Ratio	4551.00%	3978.00%
Statutory Net Income | Parent Company
Statutory Accounting Practices [Line Items]
State Insurance Department, Statutory to NAIC, Amount of Reconciling Item	$ 577	$ (7,505)	$ 2,285
Statutory Surplus | Parent Company
Statutory Accounting Practices [Line Items]
State Insurance Department, Statutory to NAIC, Amount of Reconciling Item	$ (8,320)	$ 2,635