Other Operating Expenses (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Other Operating Expenses [Abstract]
Amortization of gross deferred policy acquisition costs		$ 79,947	$ 81,734	$ 78,105
Other underwriting expenses		66,005	59,975	46,638
Reinsurance ceded credits		(24,764)	(25,932)	(23,124)
Total underwriting expenses		121,188	115,777	101,619
Operating expenses of non-insurance companies		22,240	22,679	32,406
Goodwill impairment charge	$ 3,152	0	0	3,152
Total other operating expenses		$ 143,428	$ 138,456	$ 137,177