Derivatives - Notional Amounts of Foreign Currency Forward Contracts (Details) - Foreign currency contracts - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Designated as hedges | Euro
Notional amounts of foreign currency forward contracts
Notional amounts	$ 320.2	$ 391.9
Designated as hedges | Canadian dollar
Notional amounts of foreign currency forward contracts
Notional amounts	81.8	99.0
Designated as hedges | British pound
Notional amounts of foreign currency forward contracts
Notional amounts	44.9	57.2
Designated as hedges | Australian dollar
Notional amounts of foreign currency forward contracts
Notional amounts	29.0	36.1
Designated as hedges | Swiss franc
Notional amounts of foreign currency forward contracts
Notional amounts	26.0	28.9
Designated as hedges | Other
Notional amounts of foreign currency forward contracts
Notional amounts	39.9	50.9
Not designated as hedges | Euro
Notional amounts of foreign currency forward contracts
Notional amounts	329.7	289.0
Not designated as hedges | Indian rupee
Notional amounts of foreign currency forward contracts
Notional amounts	79.2	61.0
Not designated as hedges | Canadian dollar
Notional amounts of foreign currency forward contracts
Notional amounts	45.5	110.3
Not designated as hedges | British pound
Notional amounts of foreign currency forward contracts
Notional amounts	65.4	78.1
Not designated as hedges | Mexican peso
Notional amounts of foreign currency forward contracts
Notional amounts	60.1	52.3
Not designated as hedges | Japanese yen
Notional amounts of foreign currency forward contracts
Notional amounts	27.7	37.7
Not designated as hedges | Qatari riyal
Notional amounts of foreign currency forward contracts
Notional amounts	54.4
Not designated as hedges | Australian dollar
Notional amounts of foreign currency forward contracts
Notional amounts	29.8	35.2
Not designated as hedges | Brazilian real
Notional amounts of foreign currency forward contracts
Notional amounts		32.5
Not designated as hedges | Other
Notional amounts of foreign currency forward contracts
Notional amounts	170.9	145.6
Maximum individual currency exposure within various other currencies	$ 25.0	$ 25.0