Insurance Operations - Beginning and Ending Balances and Changes in DPAC, Net of DRCC (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Deferred Policy Acquisition Costs [Roll Forward]
DPAC, beginning of year	$ 73,059	$ 64,912	$ 60,019
Capitalized Costs	174,814	144,849	130,243
Amortization of DPAC	(163,187)	(136,702)	(125,350)
DPAC, end of year	$ 84,686	$ 73,059	$ 64,912