Stock-Based Compensation - Valuation Assumptions (Details) - $ / shares	3 Months Ended	9 Months Ended
Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	0 years	5 years 2 months 12 days	5 years 4 months 2 days	5 years 4 months 6 days
Volatility	0.00%	63.00%	62.00%	65.00%
Risk-free interest rate	0.00%	1.18%	2.02%	1.29%
Dividend yield	0.00%	0.00%	0.00%	0.00%
Weighted-average estimated fair value of stock options granted (usd per share)	$ 0.00	$ 2.25	$ 2.52	$ 2.51
2015 PSU Plan [Member] \| Stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted in period (shares)	0
2015 PSU Plan [Member] \| Performance Based Options (PBOs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
PBOs granted in period (shares)	0

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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- Definition

The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

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+ Details

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- Definition

The risk-free interest rate assumption that is used in valuing an option on its own shares.

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- Definition

Weighted average expected volatility rate of share-based compensation awards.

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- Definition

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.

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No definition available.

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- Definition

Gross number of share options (or share units) granted during the period.

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No definition available.

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- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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- Definition

Expected term of share-based compensation awards, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(i)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.D.2)
-URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809

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