Accumulated Other Comprehensive Loss (Reclassification Detail) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Accumulated Other Comprehensive Income Loss [Line Items]
Net realized gain on sales of securities	$ 406		$ 385
Net impairment losses recognized in earnings	(388)		(144)
Unrealized gains (losses) on cash flow hedges	(4,405)		(2,804)
Tax effect	1,609		1,106
Cash Flow Hedges Net Of Tax	(2,796)		(1,698)
Total Reclassifications Net Of Tax	2,958
Unrealized Gains On Available For Sale Securities [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Net realized gain on sales of securities	406
Net impairment losses recognized in earnings	(388)
Net Security Gain	18
Investment Securities Tax Expense	(7)
Investment Securities Net Of Tax	11
Unrealized Losses On Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Cash Flow Hedges Net Of Tax	(2,947)
Unrealized Losses On Cash Flow Hedges [Member] | Interest Rate Contract [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Unrealized gains (losses) on cash flow hedges	4,534	[1]
Tax effect	(1,587)
Cash Flow Hedges Net Of Tax	$ 2,947

[1] For additional information, refer to "Note 13-Derivative Financial Instruments".