Share-Based Compensation - Performance Units (Details) - Performance Units - shares	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Performance Units [Abstract]
Nonvested at December 31, 2019	426,606
Granted	686,082
Vested	0
Forfeited	(254,100)
Nonvested at December 31, 2020	858,588	426,606
Weighted Average Remaining Contractual Life
Nonvested at December 31, 2019	1.6
Nonvested at December 31, 2020	1.5	1.6
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Risk-free interest rate	1.45%	2.44%
Expected volatility	49.34%	48.81%
Dividend yield	0.00%	0.00%

Performance Units [Abstract]

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Weighted Average Grant-Date Fair Value [Abstract]

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Weighted Average Remaining Contractual Life

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- Definition

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

+ References

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).

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-Topic 718
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-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(1)
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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.

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- Definition

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

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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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The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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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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