Commitments and Contingencies - Narrative (Details)				1 Months Ended
	Dec. 20, 2018 USD ($)	Nov. 03, 2017 USD ($) plaintiff	Feb. 07, 2017 plaintiff	Jan. 31, 2019 USD ($)	Jan. 31, 2018 USD ($)	Oct. 15, 2018 USD ($)
Loss Contingencies [Line Items]
Standby letters of credit				$ 152,400,000
Surety bonds				$ 463,600,000
Subsidiary ownership interest (in percent)				33.00%
Loss contingency amount accrued for probable losses				$ 12,100,000
Energy Savings Contracts
Loss Contingencies [Line Items]
Guarantee obligation				179,500,000
Performance Guarantee | Joint Venture
Loss Contingencies [Line Items]
Total guarantees				35,000,000
Minimum
Loss Contingencies [Line Items]
Amount of reasonably possible loss				0
Maximum
Loss Contingencies [Line Items]
Amount of reasonably possible loss				6,000,000
Hussein
Loss Contingencies [Line Items]
Loss contingency amount accrued for probable losses				3,300,000
Settlement amount	$ 2,100,000
Castro
Loss Contingencies [Line Items]
Loss contingency amount accrued for probable losses						$ 5,400,000
Hussein And Isse
Loss Contingencies [Line Items]
Settlement amount		$ 8,300,000
Isse
Loss Contingencies [Line Items]
Number of plaintiffs | plaintiff		220	60
Payments for legal settlements					$ 4,500,000
Hussein, Opt-Out
Loss Contingencies [Line Items]
Settlement amount				$ 1,200,000