Derivative Financial Instruments (Effect of Derivative Instruments on Earnings) (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Not Designated As Hedging Instruments [Member]
Derivative Instruments Gain Loss [Line Items]
Amount Of (Loss) Gain Recognized In Income On Derivatives	$ (1,714,000)	$ 1,545,000	$ (3,326,000)	$ 3,159,000
Cash Flow Hedges [Member] | Interest Rate Contract [Member]
Derivative Instruments Gain Loss [Line Items]
Amount Of Gain Recognized In OCI	4,010,000	831,000	6,224,000	10,030,000
Interest Expense [Member] | Cash Flow Hedges [Member] | Interest Rate Contract [Member]
Derivative Instruments Gain Loss [Line Items]
Amount Of Loss Reclassified From Accumulated OCI Into Income	(5,574,000)	(5,023,000)	(16,457,000)	(14,225,000)
Other Expense [Member] | Not Designated As Hedging Instruments [Member] | Interest Rate Contract [Member]
Derivative Instruments Gain Loss [Line Items]
Amount Of (Loss) Gain Recognized In Income On Derivatives	0	0	0	(1,000)
Other Expense [Member] | Cash Flow Hedges [Member] | Interest Rate Contract [Member]
Derivative Instruments Gain Loss [Line Items]
Amount Of Loss Recognized In Income (Ineffective Portion)	0	0	0	0
Other Income [Member] | Not Designated As Hedging Instruments [Member] | Interest Rate Contract [Member]
Derivative Instruments Gain Loss [Line Items]
Amount Of (Loss) Gain Recognized In Income On Derivatives	$ (1,714,000)	$ 1,545,000	$ (3,326,000)	$ 3,160,000