Credit Facilities (Narrative) (Details) - Revolving Credit Facility $ in Millions	Mar. 31, 2020 USD ($) LetterOfCredit
LIBOR Rate Loan
Line of Credit Facility [Line Items]
Standby letters of credit, total amount outstanding	$ 0.5
Number of standby letters of credit outstanding | LetterOfCredit	1
Remaining borrowing capacity	$ 5.5
Minimum
Line of Credit Facility [Line Items]
Liquidity requirement, minimum after specific uses	25.0
Liquidity requirement, minimum	10.0
Excess availability requirement, minimum	1.0
Maximum | Tenth Amendment
Line of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	$ 15.0