Significant Accounting Policies - Additional Cash Flow Information (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Statement Of Cash Flows [Abstract]
Cash paid for interest	$ 12,039	$ 16,007
Cash paid for income tax	32,623	27,894
Loans foreclosed and transferred to other real estate owned and foreclosed assets	2,913	4,697
Deferred gain on sale of building and parking garage	$ 1,120