Commitments and Contingent Liabilities (Details) $ in Millions	Mar. 31, 2019 USD ($)
Loss Contingencies
Letters of credit outstanding	$ 37.8
Surety bonds posted	$ 29.4

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

No definition available.

Name:	us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant