Accumulated Other Comprehensive Loss (Components Of AOCI) (Detail) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Accumulated Other Comprehensive Income Loss [Line Items]
Accumulated Other Comprehensive Loss, Beginning Balance	$ (51,566,000)
Interest Expense	24,407,000	26,194,000
Net Realized Loss (Gain) On Sales Of Securities	(8,000)	18,000
Accumulated Other Comprehensive Loss, Ending Balance	(38,649,000)
Unrealized Gains (Losses) On Investment Securities With OTTI [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Accumulated Other Comprehensive Loss, Beginning Balance	(279,000)	(839,000)
AOCI Before Reclassifications, Net Of Tax	0	(437,000)
Net Change In AOCI	0	(185,000)
Accumulated Other Comprehensive Loss, Ending Balance	(279,000)	(1,024,000)
Unrealized Gains (Losses) On Investment Securities With OTTI [Member] | Amounts Reclassified From AOCI [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Interest Expense	0	0
Net Realized Loss (Gain) On Sales Of Securities	0	388,000
Total Before Income Taxes	0	388,000
Less: Income Taxes	0	(136,000)
Net Of Income Taxes	0	252,000
Unrealized Gains (Losses) On Investment Securities All Other [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Accumulated Other Comprehensive Loss, Beginning Balance	(7,195,000)	37,521,000
AOCI Before Reclassifications, Net Of Tax	10,309,000	(3,728,000)
Net Change In AOCI	10,314,000	(3,992,000)
Accumulated Other Comprehensive Loss, Ending Balance	3,119,000	33,529,000
Unrealized Gains (Losses) On Investment Securities All Other [Member] | Amounts Reclassified From AOCI [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Interest Expense	0	0
Net Realized Loss (Gain) On Sales Of Securities	8,000	(406,000)
Total Before Income Taxes	8,000	(406,000)
Less: Income Taxes	(3,000)	142,000
Net Of Income Taxes	5,000	(264,000)
Unrealized Gains (Losses) On Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Accumulated Other Comprehensive Loss, Beginning Balance	(21,683,000)	(34,636,000)
AOCI Before Reclassifications, Net Of Tax	(903,000)	(150,000)
Net Change In AOCI	2,603,000	2,797,000
Accumulated Other Comprehensive Loss, Ending Balance	(19,080,000)	(31,839,000)
Unrealized Gains (Losses) On Cash Flow Hedges [Member] | Amounts Reclassified From AOCI [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Interest Expense	5,394,000	4,534,000
Net Realized Loss (Gain) On Sales Of Securities	0	0
Total Before Income Taxes	5,394,000	4,534,000
Less: Income Taxes	(1,888,000)	(1,587,000)
Net Of Income Taxes	3,506,000	2,947,000
Post-Retirement Benefits [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Accumulated Other Comprehensive Loss, Beginning Balance	(22,409,000)	(39,304,000)
AOCI Before Reclassifications, Net Of Tax	0	(17,000)
Net Change In AOCI	0	(17,000)
Accumulated Other Comprehensive Loss, Ending Balance	(22,409,000)	(39,321,000)
Post-Retirement Benefits [Member] | Amounts Reclassified From AOCI [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Interest Expense	0	0
Net Realized Loss (Gain) On Sales Of Securities	0	0
Total Before Income Taxes	0	0
Less: Income Taxes	0	0
Net Of Income Taxes	0	0
Accumulated Other Comprehensive Loss [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Accumulated Other Comprehensive Loss, Beginning Balance	(51,566,000)	(37,258,000)
AOCI Before Reclassifications, Net Of Tax	9,406,000	(4,332,000)
Net Change In AOCI	12,917,000	(1,397,000)
Accumulated Other Comprehensive Loss, Ending Balance	(38,649,000)	(38,655,000)
Accumulated Other Comprehensive Loss [Member] | Amounts Reclassified From AOCI [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Interest Expense	5,394,000	4,534,000
Net Realized Loss (Gain) On Sales Of Securities	8,000	(18,000)
Total Before Income Taxes	5,402,000	4,516,000
Less: Income Taxes	(1,891,000)	(1,581,000)
Net Of Income Taxes	$ 3,511,000	$ 2,935,000