ALLOWANCE FOR LOAN AND LEASE LOSSES - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010
Financing Receivable, Allowance for Credit Losses [Line Items]
Provision for loan and lease losses	$ 12,951,000	$ 6,910,000	$ 7,260,000	$ 23,895,000	$ 26,016,000
Net charge-offs	9,600,000				11,000,000
FDIC loss sharing income	12,816,000				23,435,000
Allowance for covered loan losses	46,156,000	42,835,000	48,112,000	51,044,000	31,555,000	16,493,000
Covered Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Loss share expenses primarily related to losses on covered OREO	$ 3,000,000