Leases (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012 Tenants	Dec. 31, 2011	Dec. 31, 2010
Operating Leases Future Minimum Payments Receivable Abstract
2013	$ 1,842,355
2014	1,738,439
2015	1,578,559
2016	1,400,020
2017	1,249,904
Thereafter	6,134,903
Number Of Tenants Contributing Ten Percent Or More Of Total Revenues	0
Percentage Rent	8,466	7,995	7,339
Additional Rent Due Annually From Tenant	5,000
Operating Leases Future Minimum Payments Due Abstract
2013	41,524
2014	42,321
2015	41,074
2016	37,054
2017	37,968
Thereafter	1,229,169
Rent Expense	43,528	35,436	34,611
Capital Leases Future Minimum Payments Due Abstract
2013	12,500
2014	12,500
2015	12,500
2016	12,500
2017	12,500
Thereafter	359,792
Total Minimum Obligations	422,292
Interest Portion	(182,292)
Present Value Of Net Minimum Payments	240,000
Property Leased Under Capital Leases Cost	$ 249,285