Derivative Financial Instruments (Schedule Of Interest Rate Swaps) (Details) (USD $) In Thousands	Sep. 30, 2011
Notional Amount	$ 250,000
Fair Value Gain (Loss)	(12,207)
Cash Flow [Member] | Total Interest Rate Caps [Member]
Notional Amount	60,000
Fair Value Gain (Loss)	132
Cash Flow [Member] | Total Interest Rate Swap [Member]
Notional Amount	190,000
Fair Value Gain (Loss)	(12,339)
Cash Flow [Member] | Interest Rate Swap 3 [Member]
Notional Amount	25,000
Fair Value Gain (Loss)	(30)
Cash Flow [Member] | Interest Rate Swap 4 [Member]
Notional Amount	50,000
Fair Value Gain (Loss)	(4,642)
Cash Flow [Member] | Interest Rate Swap 5 [Member]
Notional Amount	40,000
Fair Value Gain (Loss)	(3,787)
Cash Flow [Member] | Interest Rate Swap 6 [Member]
Notional Amount	50,000
Fair Value Gain (Loss)	(2,565)
Cash Flow [Member] | Interest Rate Swap 7 [Member]
Notional Amount	25,000	[1]
Fair Value Gain (Loss)	(1,315)	[1]
Cash Flow [Member] | Interest Rate Caps 1 [Member]
Notional Amount	20,000
Fair Value Gain (Loss)	44
Cash Flow [Member] | Interest Rate Caps 2 [Member]
Notional Amount	40,000
Fair Value Gain (Loss)	$ 88

[1] Forward starting in the fourth quarter of 2011