Schedule II - Condensed Financial Information of Registrant, Statements of Income and Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues:
Revenues	$ 92,804	$ 78,327	$ 72,572	$ 72,185	$ 56,904	$ 60,137	$ 54,947	$ 50,126	$ 315,888	$ 222,114	$ 186,776
Expenses [Abstract]
Other expenses									57	168	429
Total expenses									239,837	181,634	148,255
Income tax benefit									12,735	6,693	13,620
Net income	17,853	12,976	13,767	18,720	4,448	11,940	10,112	7,287	63,316	33,787	24,901
Other Comprehensive Income (Loss) [Abstract]
Total comprehensive income	$ 16,050	$ 16,218	$ 20,322	$ 25,500	$ 6,804	$ 9,987	$ 9,096	$ 2,431	78,090	28,318	31,285
Parent Company [Member]
Revenues:
Revenues									4,502	3,215	2,037
Expenses [Abstract]
Other operating expenses									2,473	2,457	2,526
Other expenses									2,742	1,598	652
Total expenses									5,215	4,055	3,178
Loss before equity in net income of subsidiaries									(713)	(840)	(1,141)
Income tax benefit									(2,714)	(1,158)	(739)
Loss before equity in net income of subsidiaries									2,001	318	(402)
Equity in net income of subsidiaries									61,315	33,469	25,303
Net income									63,316	33,787	24,901
Other Comprehensive Income (Loss) [Abstract]
Equity in other comprehensive earnings (losses) of subsidiaries									14,774	(5,469)	6,384
Total comprehensive income									$ 78,090	$ 28,318	$ 31,285