Schedule V - Valuation and Qualifying Accounts (Detail) - SEC Schedule, 12-09, Allowance, Loan and Lease Loss, Real Estate [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 18,866	$ 12,490	$ 12,895
Charged to costs and expenses	4,798	7,700	(405)
Written off	(2,331)	(1,324)	0
Change in Estimate	0	0	0
Balance at End of Period	$ 21,333	$ 18,866	$ 12,490