Common Stock and Share-Based Compensation - Restricted Stock Unit Activity (Details) - Restricted Stock Units (RSUs)	12 Months Ended
Dec. 31, 2019 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at beginning of period (shares)	980,970
Stock units issued (shares)	1,932,629
Shares issued upon vesting of stock units (shares)	(333,179)
Stock units canceled or forfeited (shares)	(1,734,882)
Outstanding at end of period (shares)	845,538
Weighted average grant date fair value (USD per share) \| $ / shares	$ 3.71
Employees
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at beginning of period (shares)	840,431
Stock units issued (shares)	1,664,256
Shares issued upon vesting of stock units (shares)	(239,509)
Stock units canceled or forfeited (shares)	(1,717,354)
Outstanding at end of period (shares)	547,824
Weighted average grant date fair value (USD per share) \| $ / shares	$ 3.09
Director
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at beginning of period (shares)	140,539
Stock units issued (shares)	268,373
Shares issued upon vesting of stock units (shares)	(93,670)
Stock units canceled or forfeited (shares)	(17,528)
Outstanding at end of period (shares)	297,714
Weighted average grant date fair value (USD per share) \| $ / shares	$ 4.84

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(3)
-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901

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- Definition

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).

+ References

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-Name Accounting Standards Codification
-Topic 718
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- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit options.

+ References

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-Publisher FASB
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- Definition

Number, after forfeiture, of shares or units issued under share-based payment arrangement. Excludes shares or units issued under employee stock ownership plan (ESOP).

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