Statutory Financial Information and Accounting Policies - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Insurance [Abstract]
Capital and surplus of the Insurance Companies	$ 58,900,000	$ 98,800,000
Statutory net (loss) income of the Insurance Companies	$ (52,000,000)	$ (7,300,000)	$ 1,000,000
Maximum dividends to be paid as a percentage of statutory capital and surplus without the prior approval of the Texas insurance commissioner	10.00%
Ordinary dividends received	$ 0