Cash Flow Information - Additional Information (Detail) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Mar. 31, 2016
Other Significant Noncash Transactions [Line Items]
Cash paid for interest	$ 33.9	$ 37.3
Net of capitalized interest	1.4	0.8
Line of credit facilities gross borrowings	200.0	270.0
Line of credit facilities gross repayments	$ 180.0	$ 150.0
Wiregrass Commons [Member]
Other Significant Noncash Transactions [Line Items]
Loans Receivable with Fixed Rates of Interest			$ 17.0