Derivative Financial Instruments (Effect of Derivative Instruments on Earnings) (Detail) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Not Designated As Hedging Instruments [Member]
Derivative Instruments Gain Loss [Line Items]
Amount Of (Loss) Gain Recognized In Income On Derivatives	$ (902,000)	$ 1,848,000	$ (1,612,000)	$ 1,615,000
Cash Flow Hedges [Member] | Interest Rate Contract [Member]
Derivative Instruments Gain Loss [Line Items]
Amount Of Gain Recognized In OCI	2,200,000	6,401,000	4,809,000	9,199,000
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	(5,489,000)	(4,668,000)	(10,883,000)	(9,202,000)
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	$ (902,000)	$ 1,848,000	$ (1,612,000)	$ 1,616,000