Derivative Financial Instruments (Net Impact On Interest Expense Related To Cash Flow Hedges) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Derivative [Line Items]
Cash flow hedges, Interest Expense	$ 351	$ 400	$ 1,018	$ 1,170
Cash flow hedges, Realized Deferred Loss (Gain)	1,932	878	5,371	1,607
Cash flow hedges, Net Impact	2,283	1,278	6,389	2,777
Fair value hedges, Interest Income	0	0	0	(61)
Fair value hedges, MTM Gain	0	0	0	(144)
Fair value hedges, Realized Deferred (Gain) Loss	(1,420)	(1,943)	(4,426)	(5,707)
Fair value hedges, Net Impact	(1,420)	(1,943)	(4,426)	(5,912)
Interest Rate Swaps On FHLB Advances [Member]
Derivative [Line Items]
Cash flow hedges, Interest Expense	351	400	1,018	1,170
Cash flow hedges, Realized Deferred Loss (Gain)	1,139	491	3,417	1,229
Cash flow hedges, Net Impact	1,490	891	4,435	2,399
Fair value hedges, Interest Income	0	0	0	(61)
Fair value hedges, MTM Gain	0	0	0	(144)
Fair value hedges, Realized Deferred (Gain) Loss	0	(24)	0	50
Fair value hedges, Net Impact	0	(24)	0	(155)
Interest Rate Swaps On Subordinated Debt [Member]
Derivative [Line Items]
Cash flow hedges, Interest Expense	0	0	0	0
Cash flow hedges, Realized Deferred Loss (Gain)	(21)	(37)	(70)	(112)
Cash flow hedges, Net Impact	(21)	(37)	(70)	(112)
Fair value hedges, Interest Income	0	0	0	0
Fair value hedges, MTM Gain	0	0	0	0
Fair value hedges, Realized Deferred (Gain) Loss	(621)	(1,120)	(2,028)	(3,359)
Fair value hedges, Net Impact	(621)	(1,120)	(2,028)	(3,359)
Interest Rate Swaps Repurchase Agreement [Member]
Derivative [Line Items]
Cash flow hedges, Interest Expense	0	0	0	0
Cash flow hedges, Realized Deferred Loss (Gain)	830	469	2,129	625
Cash flow hedges, Net Impact	830	469	2,129	625
Interest Rate Swaps On Trust Preferred Securities [Member]
Derivative [Line Items]
Cash flow hedges, Interest Expense	0	0	0	0
Cash flow hedges, Realized Deferred Loss (Gain)	(16)	(45)	(105)	(135)
Cash flow hedges, Net Impact	(16)	(45)	(105)	(135)
Interest Rate Swaps On Senior Notes [Member]
Derivative [Line Items]
Fair value hedges, Interest Income	0	0	0	0
Fair value hedges, MTM Gain	0	0	0	0
Fair value hedges, Realized Deferred (Gain) Loss	(799)	(799)	(2,398)	(2,398)
Fair value hedges, Net Impact	$ (799)	$ (799)	$ (2,398)	$ (2,398)