Stock-Based Compensation - Summary of Performance Restricted Stock Awards Activity (Details) - USD ($)	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 (target) (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	$ 1,900,000
Weighted-average remaining period for recognition of unrecognized compensation costs	2 years 3 months 18 days
Weighted average grant-date fair value granted (in dollars per share)	$ 15.00
Restricted stock awards		$ 0	$ 0
Performance Restricted Stock
Shares
Nonvested beginning balance (in shares)	226,010
Granted (in shares)	9,767
Vested (in shares)	(235,777)
Forfeited (in shares)	0
Nonvested ending balance (in shares)	0	226,010
Weighted- Average Grant Date Fair Value Per Share
Nonvested beginning balance (in dollars per share)	$ 16.62
Granted (target) (in dollars per share)	16.40
Vested (in dollars per share)	16.40
Forfeited (in dollars per share)	0
Nonvested, ending balance (in dollars per share)	0	$ 16.62
Weighted average grant-date fair value granted (in dollars per share)	$ 16.40
Fair of vested restricted stock	$ 3,900,000
Restricted stock
Weighted- Average Grant Date Fair Value Per Share
Granted (target) (in dollars per share)	$ 15.00	23.33	$ 15.46
Unrecognized compensation expense	$ 11,800,000
Weighted-average remaining period for recognition of unrecognized compensation costs	1 year 10 months 24 days
Weighted average grant-date fair value granted (in dollars per share)	$ 15.00	$ 23.33	$ 15.46
Fair of vested restricted stock	$ 7,600,000	$ 6,800,000	$ 4,300,000

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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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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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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Aggregate value of stock related to Restricted Stock Awards issued during the period.

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