Share-Based Compensation - Summary of Share-Based Compensation (income) expense (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Summary of share-based compensation expense
Share-based compensation expense before income tax		$ 1,937	$ 1,831	$ 649	$ 6,448
Income tax benefit	[1]		(460)		(1,625)
Share-based compensation expense, net of income tax		1,937	1,371	649	4,823
Performance Unit Incentive Plan ("PUP")
Summary of share-based compensation expense
Share-based compensation expense before income tax		149	1,033	(2,596)	4,013
Restricted Stock Awards And Restricted Stock Units
Summary of share-based compensation expense
Share-based compensation expense before income tax		1,698	$ 798	3,155	$ 2,435
Stock Options
Summary of share-based compensation expense
Share-based compensation expense before income tax		$ 90		$ 90

[1] ^{There was no income tax benefit for the three and nine months ended September 30, 2020 due to the valuation allowance on our deferred tax assets. Refer to Note 16 – Income Taxes.}