Long-term Debt - Debt Instrument Redemption Percentages (Details) - Senior secured notes - Senior secured second-priority lien notes (maturing December 15, 2021)	Dec. 15, 2019
2019
Debt Instrument
Redemption price percentages	105.50%
2020
Debt Instrument
Redemption price percentages	103.50%
2021
Debt Instrument
Redemption price percentages	100.00%

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

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

Name:	us-gaap_DebtInstrumentRedemptionPricePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration