Premiums Receivable - Summarizes the Activity in the Allowance for Doubtful Accounts (Parenthetical) (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Receivables [Line Items]
Provision for bad debts	$ 52	$ 2,230	$ 1,209
One-time adjustment [Member]
Receivables [Line Items]
Provision for bad debts	$ 1,700