Stock-Based Incentive Plans Stock Options (Details) - USD ($)	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross	1,368,000
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price	$ 5.52
Outstanding at December 31, 2015	5,596,000
Exercised	(208,000)
Outstanding at December 31, 2016	5,830,000	5,596,000
Vested	1,959,000
Exercisable at December 31, 2016	1,959,000
Outstanding at December 31, 2015, weighted average exercise price	$ 4.93
Exercised, weighted average exercise price	3.57
Outstanding at December 31, 2016, weighted average exercise price	5.13	$ 4.93
Vested, weighted average exercise price	4.84
Exercisable, weighted average exercise price	$ 4.84
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term	5 years 9 months
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term	5 years 9 months
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value	$ 434,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term	5 years 9 months
Outstanding at December 31, 2016, aggregate, intrinsic value	$ 856,000
Vested, aggregate intrinsic value	351,000
Exercisable, aggregate intrinsic value	434,000
Share-based Compensation Arrangment by Share-based Payment Award, Options, Granted, Fair Value	2,930,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value	$ 2,009,000	$ 2,342,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period	(926,000)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price	$ 4.90
Employee Service Share-based Compensation, Awards with Performance Condiditons, Compensation Cost Not yet Recognized	$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	25.00%
Unvested Shares with Market Based Vesting Conditions	1,687,500
Employee Service Share-based Compensation, Awards with market Cond, Compensation Cost Not yet Recognized	$ 0
Performance Based Vesting Conditions [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross	0	200,000,000
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price	$ 5.75
Share-based Compensation Arrangment by Share-based Payment Award, Options, Granted, Fair Value	$ 0	$ 487,000
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	2 months
Unrecognized Compensation Expense Options	$ 53,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments With Performance Conditions, Nonvested, Number,	102,000
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	2 years
Unrecognized Compensation Expense Options	$ 3,654,000
Market Based Vesting Conditions [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross	0	2,250,000,000
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price	$ 5.75
Share-based Compensation Arrangment by Share-based Payment Award, Options, Granted, Fair Value	$ 0	$ 5,530,000
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Market Based Vesting Conditions, price	$ 7.00
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Market Based Vesting Conditions, price	$ 10.00

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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For presentations that combine terminations, the number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan or that expired.

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Weighted average price of options that were either forfeited or expired.

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

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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Number of options outstanding, including both vested and non-vested options.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of fully vested and expected to vest options outstanding.

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As of the balance sheet date, the number of shares into which fully vested and expected to vest stock options outstanding can be converted under the option plan.

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As of the balance sheet date, the weighted-average exercise price for outstanding stock options that are fully vested or expected to vest.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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Percentage of vesting of share-based compensation awards.

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Fair value of options vested. Excludes equity instruments other than options, for example, but not limited to, share units, stock appreciation rights, restricted stock.

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Number of share options (or share units) exercised during the current period.

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