Share-based Compensation	9 Months Ended
	Sep. 30, 2021
Share-based Payment Arrangement [Abstract]
Share-based Payment Arrangement	SHARE-BASED COMPENSATIONWe grant various equity-based awards relating to Class B common stock to employees under our 2017 Omnibus Incentive Plan (“the Plan”). These awards consist of restricted shares, restricted stock units (“RSUs”), performance-based restricted shares (“performance shares”), performance-based restricted stock units (“PSUs”), and non-qualified stock options. Performance shares and PSUs granted prior to 2021 are earned based on attainment of threshold performance of earnings and return on capital targets. Beginning with grants in 2021, in addition to achievement of earnings and return on capital targets, a multiplier will be applied to performance share and PSU achievement based on relative total shareholder return (“rTSR”) against peers over the performance period.Share-based compensation expense was $3.1 million and $1.9 million for the three months ended September 30, 2021 and 2020, respectively, and $10.2 million and $4.4 million for the nine months ended September 30, 2021 and 2020, respectively. We recognize share-based compensation expense over the awards’ vesting period. As of September 30, 2021, we had $22.0 million of pre-tax unrecognized compensation cost related to outstanding share-based compensation awards expected to be recognized over a weighted average period of 2.3 years.