Summary of Significant Accounting Policies (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013 property	Dec. 31, 2012	Dec. 31, 2011
Real Estate Properties
Net reductions to rental income from amortization of capitalized above market and below market leases	$ 10,158	$ 10,274	$ 8,766
Net increases to income from discontinued operations from amortization of capitalized above market and below market leases	623	312	286
Amortization included in depreciation and amortization	47,586	45,475	32,907
Amortization included in income from discontinued operations	2,157	4,740	7,058
Future amortization of net intangible lease assets and liabilities
2014	46,204
2015	39,690
2016	32,172
2017	24,996
2018	20,876
Thereafter	57,939
Loss on asset impairment	204,036
Losses on asset impairment for properties sold	23,086
Number of properties impaired	39
Number of buildings impaired	93
Accrued environmental remediation costs	418	10,798
Other Assets, Net
Deferred financing fees	45,985	58,783
Accumulated amortization for deferred financing fees	21,455	21,623
Deferred financing fees for properties held for sale	272
Accumulated amortization for deferred financing fees for properties held for sale	132
Deferred leasing costs for properties held and used in operations	146,996	151,115
Accumulated amortization for deferred leasing costs for properties held and used in operations	46,228	49,652
Deferred leasing costs for properties held for sale	13,769	4,771
Accumulated amortization for deferred leasing costs for properties held for sale	987	2,110
Capitalized lease incentives for properties held and used in operations	20,651	20,491
Accumulated amortization for capitalized lease incentives for properties held and used in operations	5,392	3,828
Capitalized lease incentives for properties held for sale	590
Accumulated amortization for capitalized lease incentives for properties held for sale	40
Future amortization of deferred financing fees and leasing costs
Future amortization of deferred financing fees and leasing costs, in 2014	22,693
Future amortization of deferred financing fees and leasing costs, in 2015	21,041
Future amortization of deferred financing fees and leasing costs, in 2016	17,274
Future amortization of deferred financing fees and leasing costs, in 2017	14,233
Future amortization of deferred financing fees and leasing costs, in 2018	12,230
Future amortization of deferred financing fees and leasing costs, thereafter	37,827
Future amortization of capitalized lease incentives
Future amortization of capitalized lease incentives, in 2014	2,256
Future amortization of capitalized lease incentives, in 2015	2,236
Future amortization of capitalized lease incentives, in 2016	2,225
Future amortization of capitalized lease incentives, in 2017	2,152
Future amortization of capitalized lease incentives, in 2018	2,069
Future amortization of capitalized lease incentives, thereafter	4,321
Accounting Policy for Derivative Instruments
Fair value of derivative instrument	11,706	16,624
Income Taxes
Minimum percentage of likelihood of realization of tax benefits	50.00%
Foreign currency translation adjustments	(26,647)	17,071
Above market leases
Real Estate Properties
Capitalized leases for properties held and used in operations	127,944	190,402
Accumulated amortization of capitalized leases for properties held and used in operations	48,841	56,374
Capitalized leases for properties held for sale	2,047	1,191
Accumulated amortization of capitalized leases for properties held for sale	0	1,060
Below market leases
Real Estate Properties
Capitalized leases for properties held and used in operations	56,815	106,643
Accumulated amortization of capitalized leases for properties held and used in operations	22,880	37,339
Capitalized leases for properties held for sale	4,996	92
Accumulated amortization of capitalized leases for properties held for sale	2,926	71
In place leases
Real Estate Properties
Capitalized leases for properties held and used in operations	282,754	393,068
Accumulated amortization of capitalized leases for properties held and used in operations	106,045	99,340
Capitalized leases for properties held for sale	9,351	2,297
Accumulated amortization of capitalized leases for properties held for sale	$ 4,461	$ 1,975