Loans and Leases and the Allowance for Credit Losses - Interest Income Recognized on Loans (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment	$ 894,854	$ 1,064,446
Interest income recognized, Total	6,581	7,816
Interest income recognized, Cash basis	4,264	5,189
Commercial, Financial, Leasing, etc. [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment	134,306	167,793
Interest income recognized, Total	548	2,434
Interest income recognized, Cash basis	548	2,434
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment	185,425	194,446
Interest income recognized, Total	926	303
Interest income recognized, Cash basis	926	303
Residential Builder and Developer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment	101,253	183,853
Interest income recognized, Total	74	140
Interest income recognized, Cash basis	74	65
Other commercial construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment	87,292	98,318
Interest income recognized, Total	1,087	635
Interest income recognized, Cash basis	1,087	635
Residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment	174,168	188,075
Interest income recognized, Total	1,400	1,470
Interest income recognized, Cash basis	902	922
Residential Alt-A [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment	139,651	156,971
Interest income recognized, Total	1,626	1,740
Interest income recognized, Cash basis	559	591
Home equity lines and loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment	15,676	12,454
Interest income recognized, Total	121	167
Interest income recognized, Cash basis	29	39
Automobile [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment	39,383	47,606
Interest income recognized, Total	625	776
Interest income recognized, Cash basis	87	146
Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment	17,700	14,930
Interest income recognized, Total	174	151
Interest income recognized, Cash basis	$ 52	$ 54