Investments in and Advances to Joint Ventures - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Schedule Of Equity Method Investments [Line Items]
Letters of credit outstanding amount	$ 219.2		$ 219.2		$ 193.1
Write-down on unconsolidated joint venture	1.6		5.1
Decrease in operating income	1.6		5.1
Decrease in net income net of tax	$ 1.2		$ 3.8
Decrease in earnings per share diluted	$ 0.01		$ 0.03
Unconsolidated Joint Ventures
Schedule Of Equity Method Investments [Line Items]
Net distributions from and sale proceeds for unconsolidated joint ventures	$ 1.5	$ 5.6	$ 6.8	$ 12.1
Consolidated Joint Ventures
Schedule Of Equity Method Investments [Line Items]
Letters of credit outstanding amount	$ 67.5		$ 67.5		$ 59.3