Subsequent Events (Narrative) (Details) - Credit 2019 Agreement [Member] - First Modification Agreement [Member] - Subsequent Event [Member] - USD ($) $ in Millions	Jul. 08, 2020	Jul. 07, 2020
Subsequent Event [Line Items]
Capital expenditures	$ 8.5
Domestic cash balances, prohibited holding amount	$ 5.0
Percentage added to LIBOR rate	3.00%	1.85%
Unused credit commitment fee	0.50%	0.20%
Minimum [Member] \| August 31, 2020 Through May 31, 2021 [Member]
Subsequent Event [Line Items]
Minimum liquidity	$ 13.0
Minimum [Member] \| May 31, 2021 [Member]
Subsequent Event [Line Items]
Minimum liquidity	$ 8.0

Future cash outflow to pay for purchases of fixed assets that have occurred.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4332-108586

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4313-108586

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4304-108586

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration