Nature of Operations and Basis of Presentation (Details)		3 Months Ended		9 Months Ended
	Sep. 18, 2017 segment	Sep. 30, 2019 USD ($) state	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($) segment state variable_interest_entities	Sep. 30, 2018 USD ($)	Jan. 01, 2019 USD ($)	Dec. 31, 2018 USD ($)	Jan. 01, 2018 USD ($)
Segment Reporting Information [Line Items]
Number of business segments | segment	2			1
Payment for income taxes				$ 1,556,000	$ 24,055,000
Federal tax refund received				5,401,000	1,503,000
Interest payments				0	0
Federal income tax expense (benefit)		$ (2,186,000)	$ 1,528,000	7,595,000	771,000
Liability for unrecognized tax benefits		0		$ 0			$ 0
Number of variable interest entities | variable_interest_entities				1
Initial investment in variable interest entity		7,500,000		$ 7,500,000
VIE maximum exposure		7,500,000		7,500,000
Operating lease right-of-use assets		16,924,000		16,924,000
Lease liability		$ 17,389,000		$ 17,389,000
Cumulative effect of change in accounting principle						$ 513,000		$ 0
Property and Casualty Insurance
Segment Reporting Information [Line Items]
Number of states in which we are licensed as insurer | state		46		46
Continuing and Discontinuing Operations
Segment Reporting Information [Line Items]
Federal income tax expense (benefit)				$ 7,595,000	$ 8,878,000
Accounting Standards Update 2016-02
Segment Reporting Information [Line Items]
Operating lease right-of-use assets						19,800,000
Lease liability						20,300,000
Retained earnings
Segment Reporting Information [Line Items]
Cumulative effect of change in accounting principle						513,000		$ (191,244,000)
Retained earnings | Accounting Standards Update 2016-02
Segment Reporting Information [Line Items]
Cumulative effect of change in accounting principle						387,000
Retained earnings | Accounting Standards Update 2016-01
Segment Reporting Information [Line Items]
Cumulative effect of change in accounting principle						$ 126,000