Real Estate - Portfolio (Summary Of Real Estate Subject To Operating Leases) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Property Subject to or Available for Operating Lease [Line Items]
Real estate dubject to operating leases, gross	$ 3,700,544	$ 3,434,932
Less accumulated depreciation and amortization	(302,435)	(270,023)
Real estate subject to operating leases before work in process	3,398,109	3,164,909
Real estate subject to operating leases, net	3,485,819	3,225,119
Land And Improvements [Member]
Property Subject to or Available for Operating Lease [Line Items]
Real estate subject to operating leases, gross	1,390,175	1,315,339
Buildings And Improvements [Member]
Property Subject to or Available for Operating Lease [Line Items]
Buildings and improvements	2,309,079	2,118,303
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	$ 87,710	$ 60,210