Real Estate - Portfolio (Summary Of Real Estate Subject To Operating Leases) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Property Subject to or Available for Operating Lease [Line Items]
Real estate subject to operating leases, gross	$ 4,458,614	$ 4,036,207
Less accumulated depreciation and amortization	(370,278)	(331,432)
Real estate subject to operating leases before work in process	4,088,336	3,704,775
Accounted for using the operating method, net of accumulated depreciation and amortization	4,158,943	3,791,282
Land And Improvements [Member]
Property Subject to or Available for Operating Lease [Line Items]
Real estate subject to operating leases, gross	1,613,418	1,471,831
Buildings And Improvements [Member]
Property Subject to or Available for Operating Lease [Line Items]
Buildings and improvements	2,843,906	2,563,086
Leasehold Interests [Member]
Property Subject to or Available for Operating Lease [Line Items]
Leasehold interests	1,290	1,290
Work In Progress [Member]
Property Subject to or Available for Operating Lease [Line Items]
Work in progess	$ 70,607	$ 86,507