Long-Term Debt - Repurchases of Debt Securities (Details) - Convertible Notes Payable - 4.0% convertible notes due 2027 - USD ($)	Feb. 15, 2019	Jun. 30, 2019	Jun. 07, 2019	Sep. 30, 2018
Debt Instrument [Line Items]
Principal amount of convertible notes repurchased	$ 19,000,000	$ 5,000,000	$ 5,000,000
Interest rate		4.00%		4.00%
Redemption price	100.00%

Contractual interest rate for funds borrowed, under the debt agreement.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

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- Definition

Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph e
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

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Face (par) amount of the original debt instrument that was repurchased.

+ References

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