Revenue - Estimated Minimum Revenue Expected to be Recognized in Future Related to Unsatisfied Performance Obligations (Details) - Fixed Price Contract [Member] $ in Millions	Jun. 30, 2020 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2020-07-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Fixed consideration to be recognized	$ 270.6
Estimated remaining duration of contracts	6 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2021-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Fixed consideration to be recognized	$ 515.0
Estimated remaining duration of contracts	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2022-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Fixed consideration to be recognized	$ 3,202.7
Estimated remaining duration of contracts