Cash Flow Information - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Other Significant Noncash Transactions [Line Items]
Cash paid for interest	$ 17.3	$ 17.0
Net of capitalized interest	0.7	0.1
Line of credit facilities gross borrowings	70.0	$ 210.0
Line of credit facilities gross repayments	20.0
Wiregrass Commons [Member]
Other Significant Noncash Transactions [Line Items]
Loans Receivable with Fixed Rates of Interest	$ 17.0