FDIC loss share (expense) income (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
F D I C Loss Share Expense Income [Line Items]
(Amortization) accretion of indemnification asset	$ (48,946)		$ (40,204)
80% mirror accounting on credit impairment losses	15,090	[1]	14,045	[1]
80% mirror accounting on reimbursable expenses	12,745		7,783
80% mirror accounting on recoveries on covered assets, including rental income on OREOs, subject to reimbursement to the FDIC	(4,392)		(1,101)
80% mirror accounting on discount accretion on loans and unfunded commitments accounted for under ASC 310-20	0		(193)
Change in true-up payment obligation	1,168		(6,775)
Other	129		179
FDIC loss share (expense) income	$ (24,206)		$ (26,266)

[1] Reductions in expected cash flows for ASC 310-30 loans, which may impact the provision for loan losses, may consider reductions in both principal and interest cash flow expectations. The amount covered under the FDIC loss sharing agreements for interest not collected from borrowers is limited under the agreements (approximately 90 days); accordingly, these amounts are not subject fully to the 80% mirror accounting.