Notes Payable - 8.375% Notes due 2026 - Redemption Percentage (Details) - 8.375% Notes due 2026 - Notes Payable	6 Months Ended
Jun. 30, 2017
From and including March 15, 2018 to and including March 14, 2019
Notes Payable
Payment start date	Mar. 15, 2018
Payment end date	Mar. 14, 2019
Redemption Percentage	108.00%
From and including March 15, 2019 to and including March 14, 2020
Notes Payable
Payment start date	Mar. 15, 2019
Payment end date	Mar. 14, 2020
Redemption Percentage	105.50%
From and including March 15, 2020 to and including March 14, 2021
Notes Payable
Payment start date	Mar. 15, 2020
Payment end date	Mar. 14, 2021
Redemption Percentage	102.75%
From and including March 15, 2021 and thereafter
Notes Payable
Payment start date	Mar. 15, 2021
Redemption Percentage	100.00%

End date of debt instrument redemption period, in CCYY-MM-DD format.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-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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Start date of debt instrument redemption period, in CCYY-MM-DD format.

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

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