Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Real estate properties:
Land	$ 161,875		$ 162,843
Buildings, improvements and lease intangibles	2,625,538		2,521,226
Personal property	19,100		18,221
Construction in progress			61,152
Land held for development	25,171		25,176
Total real estate properties	2,831,684		2,788,618
Less accumulated depreciation	(586,725)		(516,747)
Total real estate properties, net	2,244,959		2,271,871
Cash and cash equivalents	6,776		4,738
Mortgage notes receivable	162,191	[1],[2]	97,381	[1],[2]
Assets held for sale and discontinued operations, net	3,337		28,650
Other assets, net	122,709		118,382
Total assets	2,539,972		2,521,022
Liabilities:
Notes and bonds payable	1,293,044	[3]	1,393,537	[3]
Accounts payable and accrued liabilities	65,678		72,217
Liabilities of discontinued operations	131		518
Other liabilities	60,175		49,944
Total liabilities	1,419,028		1,516,216
Commitments and contingencies
Stockholders' Equity:
Preferred stock, $.01 par value; 50,000,000 shares authorized; none issued and outstanding
Common stock, $.01 par value; 150,000,000 shares authorized; 87,514,336 and 77,843,883 shares issued and outstanding at December 31, 2012 and 2011, respectively.	875		779
Additional paid-in capital	2,100,297		1,894,604
Accumulated other comprehensive loss	(2,092)		(3,332)
Cumulative net income attributable to common stockholders	801,416		795,951
Cumulative dividends	(1,779,552)		(1,683,196)
Total stockholders’ equity	1,120,944		1,004,806
Total liabilities and stockholders' equity	$ 2,539,972		$ 2,521,022

[1] Total mortgage notes as of December 31, 2012 had an aggregate total cost of $162.2 million for federal income tax purposes.

[2] Level 2 - Fair value based on quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-driven valuations in which significant inputs and significant value drivers are observable in active markets.

[3] Level 3 - Fair value derived from valuation techniques in which one of more significant inputs or significant value drivers are unobservable.