Financing Activity - Mortgage Loan Activity (Parenthetical) (Detail) (Subsequent Event [Member], Two Thousand Thirteen Revolving Credit Facility [Member], USD $) In Millions, unless otherwise specified	1 Months Ended
	Jul. 31, 2014
Subsequent Event [Member] | Two Thousand Thirteen Revolving Credit Facility [Member]
Mortgage Loan Activity [Line Items]
Proceeds from Sales of real estate assets used to pay unsecured debt	$ 50.0