Information Regarding Concentration of Reinsurance Recoverables and Ratings Profile of its Reinsurers (Parenthetical) (Detail) - Reinsurance Recoverable - Reinsurer Concentration Risk	12 Months Ended
	Dec. 31, 2016
Ceded Credit Risk [Line Items]
Reinsurance recoverable as percentage of total reinsurance recoverables	100.00%	[1],[2]
A (Excellent) or higher
Ceded Credit Risk [Line Items]
Reinsurance recoverable as percentage of total reinsurance recoverables	94.00%

[1] Approximately 94 percent of our reinsurance recoverables balance as of December 31, 2016 was due from reinsurers having an A.M. Best financial strength rating of A (Excellent) or higher.

[2] Reinsurance recoverables reflect amounts due from one or more reinsurance subsidiaries of the listed company.