Deferred Policy Acquisition Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Balance, beginning of year	$ 215,131	$ 198,151	$ 200,826
Policy acquisition costs deferred	620,120	589,144	552,675
Amortization	(602,085)	(572,164)	(555,350)
Balance, end of year	$ 233,166	$ 215,131	$ 198,151