General - Long-Term Debt, Finance Lease and Deferred Financing Obligations - Letter of Credit Agreement (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Long Term Debt, Capital Lease and Deferred Financing Obligations
Letters of credit outstanding	$ 33.0	$ 32.1

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