Supplemental Information to Statement of Cash Flows - Cash Flow Information (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Supplemental Cash Flow Information [Line Items]
Interest Expense Capitalized in Connection with Development Activity	$ 742	$ 1,623
Supplemental Schedule of Non-cash Investing and Financing Activities:
Distributions Payable	11,891
Exchange of Limited Partnership Units for General Partnership Units:
Conversion of Limited Partner Units to General Partner Units	0	0
Assumption of Liabilities in Connection with the Acquisition of Real Estate	183	298
Accounts Payable Related to Construction in Progress and Additions to Investment in Real Estate	17,626	8,672
Write-off of Fully Depreciated Assets	(16,687)	(29,561)
General Partner Units
Exchange of Limited Partnership Units for General Partnership Units:
Conversion of Limited Partner Units to General Partner Units	1,333	804
Limited Partner Units
Exchange of Limited Partnership Units for General Partnership Units:
Conversion of Limited Partner Units to General Partner Units	(1,333)	(804)
General and Limited Partner Units
Supplemental Schedule of Non-cash Investing and Financing Activities:
Distributions Payable	11,891	9,745
Preferred Units
Supplemental Schedule of Non-cash Investing and Financing Activities:
Distributions Payable	$ 0	$ 2,056