Stock-Based Compensation - Summary of Grants Awarded (Details) - $ / shares	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock	1,676,634	1,586,590	1,000,690
Grant date fair value of restricted stock	$ 5.13	$ 4.90	$ 7.63
Performance shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock	1,343,953	946,000	869,421
Grant date fair value of restricted stock	$ 3.95	$ 4.71	$ 7.41

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).

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)(2)(iii)(1)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

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- Definition

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

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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