Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Loss Contingencies [Line Items]
Line of credit, performance and payment bonds	$ 197.6	$ 192.2
Operating Partnership [Member]
Loss Contingencies [Line Items]
Outstanding letters of credit	$ 8.0	$ 8.5

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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