Summary of Significant Accounting Policies - Reclassifications (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Reclassifications [Line Items]
Land	$ 182,313	$ 183,651
Building and improvements	2,102,743	2,044,113
Lease intangibles	360,937	352,884
Real estate investments, gross	2,667,131	2,580,648
Accumulated depreciation and amortization	(392,102)	(349,118)
Real estate investments, net	2,275,029	2,231,530
Accounts and other receivables, net	17,217	13,317
Receivables and other assets, net	97,289	84,970
Other intangibles, net	42,237	44,011
Scenario, Previously Reported
Reclassifications [Line Items]
Land		0
Building and improvements		0
Lease intangibles		0
Real estate investments, gross		0
Accumulated depreciation and amortization		0
Real estate investments, net		1,992,607
Accounts and other receivables, net		13,317
Receivables and other assets, net		71,653
Other intangibles, net		282,934
As Reclassified
Reclassifications [Line Items]
Land		183,651
Building and improvements		2,044,113
Lease intangibles		352,884
Real estate investments, gross		2,580,648
Accumulated depreciation and amortization		(349,118)
Real estate investments, net		2,231,530
Accounts and other receivables, net		0
Receivables and other assets, net		84,970
Other intangibles, net		$ 44,011