Derivatives and Hedging Activities (Details) (USD $) In Thousands, except Share data, unless otherwise specified	9 Months Ended	1 Months Ended				9 Months Ended		12 Months Ended		9 Months Ended
	Sep. 30, 2012	Jan. 31, 2012 Interest Rate Swap [Member]	Sep. 30, 2012 Designated as Hedging Instrument [Member] Interest Rate Swap [Member] Accounts Payable And Other Liabilities [Member]	Dec. 31, 2011 Designated as Hedging Instrument [Member] Interest Rate Swap [Member] Accounts Payable And Other Liabilities [Member]	Sep. 30, 2012 Designated as Hedging Instrument [Member] Cash Flow Hedging [Member] Interest Rate Swap [Member]	Sep. 30, 2012 Designated as Hedging Instrument [Member] Cash Flow Hedging [Member] Interest Rate Swap [Member] Interest Expense [Member]	Sep. 30, 2011 Designated as Hedging Instrument [Member] Cash Flow Hedging [Member] Interest Rate Swap [Member] Interest Expense [Member]	Dec. 31, 2008 Not Designated as Hedging Instrument [Member] Forward Contracts [Member]	Oct. 31, 2011 Not Designated as Hedging Instrument [Member] Forward Contracts [Member]	Sep. 30, 2012 Not Designated as Hedging Instrument [Member] Forward Contracts [Member] Change in value of forward equity commitment [Member]	Sep. 30, 2011 Not Designated as Hedging Instrument [Member] Forward Contracts [Member] Change in value of forward equity commitment [Member]	Sep. 30, 2012 Secured Revolving Credit Facility, Expiring January 2015 [Member] Secured Term Loan [Member]
Derivative [Line Items]
Line of Credit Facility, Amount Outstanding												$ 215,000
Derivative Instrument, Settlement Amount		3,539
Amount of Loss Reclassified from Accumulated OCI into Income (Effective Portion)		1,837				415	2,156
Expected Amount Of Derivative Related Interest To Be Reclassified To Interest Expense Over The Next 12 Months	2,044
Derivative, Number of Instruments Held					4
Notional Amount of Derivatives					215,000
Forward Contract Indexed to Issuer's Equity, Shares								3,500,000
Accelerated Share Repurchases, Final Price Paid Per Share								$ 5.60
Amount of Loss Recognized in Income on Derivative										0	(4,318)
Cash Settlement Value Net									4,024
Forward Contract Indexed To Issuers Equity Share Settlement Shares Retired									3,974,645
Derivative Liabilities			7,114	3,236
Amount of Loss Recognized in OCI on Derivatives (Effective Portion)						$ (8,746)	$ (814)