Credit Facilities and Mortgage Notes Payable - Unsecured Credit Facility - Additional Information (Detail) (USD $) In Millions, unless otherwise specified						12 Months Ended		1 Months Ended	12 Months Ended		1 Months Ended	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2013 Minimum [Member] Libor Rate [Member]	Dec. 31, 2013 Minimum [Member] Base Rate [Member]	Dec. 31, 2013 Maximum [Member] Libor Rate [Member]	Dec. 31, 2013 Maximum [Member] Base Rate [Member]	Dec. 31, 2013 Term Loan [Member]	Dec. 31, 2013 Revolving Credit Facility [Member]	Feb. 28, 2014 Revolving Credit Facility [Member] Subsequent Event [Member]	Dec. 31, 2013 Revolving Credit Facility [Member] Subsequent Event [Member]	Dec. 31, 2013 Letter of Credit [Member]	May 01, 2013 Unsecured Credit Facility [Member]	Dec. 31, 2013 Unsecured Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility agreement date											May 01, 2013
Credit Facility maximum borrowing capacity						$ 225	$ 350	$ 400	$ 400			$ 575
Unsecured Credit Facility term						5 years	4 years
Line of credit accordion feature												100
Increase the amount of line of credit facility												675
Additional letter of credit outstanding										3.0
Leverage Ratio		2.10%	1.10%	2.85%	1.85%
Line of credit facility interest rate outstanding amounts	2.53%
Unsecured revolving credit facility								$ 50	$ 50