Stock-Based Compensation - Summary of TSR Award Activity (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Shares
Nonvested beginning balance (in shares)	1,031,772
Granted (in shares)	786,006
Vested (in shares)	(610,804)
Forfeited (in shares)	(99,108)
Nonvested ending balance (in shares)	1,107,866	1,031,772
Weighted- Average Grant Date Fair Value Per Share
Nonvested beginning balance (in dollars per share)	$ 15.20
Granted (in dollars per share)	15.00
Vested (in dollars per share)	12.45
Forfeited (in dollars per share)	15.53
Nonvested, ending balance (in dollars per share)	$ 16.58	$ 15.20
Unrecognized compensation expense	$ 1.9
Weighted-average remaining period for recognition of unrecognized compensation costs	2 years 3 months 18 days
Total Stockholder Return Restricted Stock Awards
Shares
Nonvested beginning balance (in shares)	306,230
Granted (in shares)	220,971
Vested (in shares)	0
Forfeited (in shares)	(35,430)
Nonvested ending balance (in shares)	491,771	306,230
Weighted- Average Grant Date Fair Value Per Share
Nonvested beginning balance (in dollars per share)	$ 30.56
Granted (in dollars per share)	23.43	$ 39.92	$ 22.76
Vested (in dollars per share)	0
Forfeited (in dollars per share)	27.47
Nonvested, ending balance (in dollars per share)	$ 27.58	$ 30.56
Unrecognized compensation expense	$ 6.2
Weighted-average remaining period for recognition of unrecognized compensation costs	1 year 9 months 18 days

Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Amount of cost to be recognized for nonvested award under share-based payment arrangement. Excludes share and unit options.

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

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Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

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

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

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The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

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