Real Estate Investments - Development Activities (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended					3 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011	Sep. 30, 2013
Proceeds from senior corporate credit facility	$ 1,889,800	[1]	$ 0	[1]	$ 0
Columbia, South Carolina [Member]
Investment Amount, Total	22,070
Number of Square Feet	450,000
The Woodlands, Texas [Member]
Investment Amount, Total	34,032
Number of Square Feet	150,000
Proceeds from senior corporate credit facility	$ 17,000
Percentage of Square Footage Leased						95.00%
Developer [Member] | The Woodlands, Texas [Member]
Cost Overruns Percentage Split	50.00%
Equity Contributions Percentage	10.00%
Parent [Member] | The Woodlands, Texas [Member]
Equity Contributions Percentage	90.00%

[1] For discussion on the restatement adjustments, see Note 2 - Restatement of Previously Issued Financial Statements.