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Condensed Guarantor and Non-Guarantor Financial Information, Narrative (Details) - USD ($) | Jun. 30, 2018 | May 15, 2016
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Condensed Financial Statements, Captions |  |
Ownership interest by parent | 100.00% |
Senior Notes Due 2024 | Senior Notes |  |
Condensed Financial Statements, Captions |  |
Debt principal amount |  | $ 375,000,000

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- Definition Face (par) amount of debt instrument at time of issuance. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399 + Details
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