Consolidated Balance Sheets Consolidated Balance Sheet (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Accounts receivable, allowance	$ 1,576	$ 3,374
Straight-line rent receivable, allowance	9,350	6,091
Deferred finance costs, accumulated amortization	37,016	48,218
Accumulated amortization, aggregate deferred leasing and acquired lease related intangible asset	394,049	372,047
Preferred shares, par value	$ 0.01	$ 0.01
Preferred shares, shares authorized	5,000,000	5,000,000
Preferred shares, shares issued	1,791,000	2,503,000
Preferred Stock, Shares Outstanding	1,791,000	2,503,000
Common shares, par value	$ 0.01	$ 0.01
Common shares, shares authorized	400,000,000	400,000,000
Common shares, shares issued	326,399,000	279,423,000
Common shares, shares outstanding	326,399,000	279,423,000
Subsidiary of Common Parent [Member]
Accounts receivable, allowance	1,576	3,374
Straight-line rent receivable, allowance	9,350	6,091
Deferred finance costs, accumulated amortization	37,016	48,218
Accumulated amortization, aggregate deferred leasing and acquired lease related intangible asset	$ 394,049	$ 372,047
Common equity, General Partner Units issued	326,399,000	279,423,000
Common equity, General Partner Units outstanding	326,399,000	279,423,000
Preferred Units, Issued	1,791,000	2,503,000
Preferred Units, Outstanding	1,791,000	2,503,000
Limited Partner Units issued	4,387,000	4,419,000
Limited Partner Units outstanding	4,387,000	4,419,000