Commitments and Contingencies - Narrative (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Loss Contingencies [Line Items]
Outstanding performance and surety bonds	$ 342.9
Non-refundable deposits	73.2
Remaining purchase price of land	0.7
Lease liability	19.4	$ 14.6
Finance lease obligation	$ 18.5
Minimum | Land, Banking Arrangement
Loss Contingencies [Line Items]
Non-refundable deposit of total purchase price, percentage	15.00%
Maximum | Land, Banking Arrangement
Loss Contingencies [Line Items]
Non-refundable deposit of total purchase price, percentage	25.00%
Project construction commitment
Loss Contingencies [Line Items]
Other commitment	$ 297.9
Accrued Expenses
Loss Contingencies [Line Items]
Lease liability	$ 37.9	$ 14.6