Fair Value Measurement of Assets and Liabilities - Assets and Liabilities Measured at Fair Value on Recurring and Non-Recurring Basis (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Fair Value Disclosures [Abstract]
Unpaid principal balances of loans held for sale	$ 4.9	$ 10.4
Covered real estate owned	$ 8.4	$ 7.6