Other Operating Expenses (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Other Operating Expenses [Abstract]
Amortization of gross deferred policy acquisition costs		$ 81,734	$ 78,105	$ 70,574
Other underwriting expenses		59,975	46,638	37,230
Reinsurance ceded credits		(25,932)	(23,124)	(23,187)
Total underwriting expenses		115,777	101,619	84,617
Operating expenses of non-insurance companies		22,679	32,406	28,977
Goodwill impairment charge	$ 3,152	0	3,152	0
Total other operating expenses		$ 138,456	$ 137,177	$ 113,594