Stock Compensation - Fair Value Assuptions (Details) - $ / shares	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value (in dollars per share)	$ 2.39	$ 2.51
Risk-free interest rate	2.08%	1.32%
Expected life	6 years	6 years
Estimated volatility factor	57.14%	48.30%
Expected dividends	0.00%	0.00%
Stock appreciation rights (SAR)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of awards (in dollars per share)	$ 2.21	$ 0.32
Risk-free interest rate	2.22%	1.87%
Expected life	3 years 11 months 12 days	4 years 8 months 23 days
Estimated volatility factor	54.50%	54.50%
Expected dividends	0.00%	0.00%
Restricted stock units (RSU)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of awards (in dollars per share)	$ 4.32	$ 5.32
Phantom stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of awards (in dollars per share)	$ 4.35	$ 6.11
Director shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	1.96%
Expected life	6 years 5 months 19 days
Estimated volatility factor	31.16%
Expected dividends	0.00%

The weighted average fair value at grant date for nonvested equity-based awards issued 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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- 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

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.

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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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