Components of Troubled Debt Restructured Loans and Leases (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013
Troubled Debt Restructurings [Line Items]
Loans receivable	$ 2,396,995	$ 2,446,111	$ 1,627,272
Commercial and industrial
Troubled Debt Restructurings [Line Items]
Loans receivable	299,184		79,345
SBA
Troubled Debt Restructurings [Line Items]
Loans receivable	26,541		35,662
Real estate 1-4 family first mortgage
Troubled Debt Restructurings [Line Items]
Loans receivable	1,158,863		1,009,092
HELOC, home equity loans, and other consumer credit
Troubled Debt Restructurings [Line Items]
Loans receivable	122,763		21,956
Non Traditional Mortgages
Troubled Debt Restructurings [Line Items]
Loans receivable	269,410	309,597
Non Traditional Mortgages | Real estate 1-4 family first mortgage
Troubled Debt Restructurings [Line Items]
Loans receivable, Consumer	120,668	156,490
Loans receivable	120,668	156,490
Non Traditional Mortgages | Heloc First Liens
Troubled Debt Restructurings [Line Items]
Loans receivable, Consumer	143,708	147,705
Loans receivable	143,708	147,705
Non Traditional Mortgages | HELOC, home equity loans, and other consumer credit
Troubled Debt Restructurings [Line Items]
Loans receivable, Consumer	113	113
Loans receivable	113	113
Non Traditional Mortgages | Troubled Debt Restructured Loans
Troubled Debt Restructurings [Line Items]
Loans receivable	3,463	3,468
Non Traditional Mortgages | Troubled Debt Restructured Loans | Heloc First Liens
Troubled Debt Restructurings [Line Items]
Loans receivable, Consumer	3,463	3,468
Traditional Loans
Troubled Debt Restructurings [Line Items]
Loans receivable	1,814,162	1,797,228
Traditional Loans | Commercial and industrial
Troubled Debt Restructurings [Line Items]
Loans receivable, Commercial	297,646	283,743
Traditional Loans | Real estate mortgage
Troubled Debt Restructurings [Line Items]
Loans receivable, Commercial	545,968	514,869
Traditional Loans | SBA
Troubled Debt Restructurings [Line Items]
Loans receivable, Commercial	23,064	23,740
Traditional Loans | Real estate 1-4 family first mortgage
Troubled Debt Restructurings [Line Items]
Loans receivable, Consumer	602,448	667,526
Traditional Loans | HELOC, home equity loans, and other consumer credit
Troubled Debt Restructurings [Line Items]
Loans receivable, Consumer	115,973	108,888
Traditional Loans | Troubled Debt Restructured Loans
Troubled Debt Restructurings [Line Items]
Loans receivable	3,748	3,809
Traditional Loans | Troubled Debt Restructured Loans | Real estate mortgage
Troubled Debt Restructurings [Line Items]
Loans receivable, Commercial	181	194
Traditional Loans | Troubled Debt Restructured Loans | SBA
Troubled Debt Restructurings [Line Items]
Loans receivable, Commercial	10	10
Traditional Loans | Troubled Debt Restructured Loans | Real estate 1-4 family first mortgage
Troubled Debt Restructurings [Line Items]
Loans receivable, Consumer	3,557	3,605
Purchased loans
Troubled Debt Restructurings [Line Items]
Loans receivable	313,423	339,286
Purchased loans | Commercial and industrial
Troubled Debt Restructurings [Line Items]
Loans receivable, Commercial	1,538	4,028
Purchased loans | Real estate mortgage
Troubled Debt Restructurings [Line Items]
Loans receivable, Commercial	14,613	15,014
Purchased loans | SBA
Troubled Debt Restructurings [Line Items]
Loans receivable, Commercial	3,477	3,688
Purchased loans | Real estate 1-4 family first mortgage
Troubled Debt Restructurings [Line Items]
Loans receivable, Consumer	292,039	314,820
Purchased loans | HELOC, home equity loans, and other consumer credit
Troubled Debt Restructurings [Line Items]
Loans receivable, Consumer	1,756	1,736
Purchased loans | Troubled Debt Restructured Loans
Troubled Debt Restructurings [Line Items]
Loans receivable	5,380	5,393
Purchased loans | Troubled Debt Restructured Loans | Commercial and industrial
Troubled Debt Restructurings [Line Items]
Loans receivable, Commercial	88	85
Purchased loans | Troubled Debt Restructured Loans | Real estate mortgage
Troubled Debt Restructurings [Line Items]
Loans receivable, Commercial	2,847	2,868
Purchased loans | Troubled Debt Restructured Loans | SBA
Troubled Debt Restructurings [Line Items]
Loans receivable, Commercial	689	704
Purchased loans | Troubled Debt Restructured Loans | HELOC, home equity loans, and other consumer credit
Troubled Debt Restructurings [Line Items]
Loans receivable, Consumer	$ 1,756	$ 1,736