Consolidated Statements of Stockholders' Equity - USD ($) $ in Millions	Total	Previously Reported	ASU No. 2018-02	Common Stock	Common Stock Previously Reported	Additional Paid-In Capital	Additional Paid-In Capital Previously Reported	Accumulated Other Comprehensive Loss	Accumulated Other Comprehensive Loss Previously Reported	Accumulated Other Comprehensive Loss ASU No. 2018-02	Retained Earnings (Accumulated Deficit)	Retained Earnings (Accumulated Deficit) Previously Reported	Retained Earnings (Accumulated Deficit) ASU No. 2018-02	Treasury Stock	Treasury Stock Previously Reported	Noncontrolling Interest	Noncontrolling Interest Previously Reported
Beginning balance (deficit) at Dec. 31, 2017	$ 313.1	$ 313.1	$ 0.0			$ 254.6	$ 254.6	$ (1.8)	$ (1.2)	$ (0.6)	$ 67.6	$ 67.0	$ 0.6	$ (7.5)	$ (7.5)	$ 0.2	$ 0.2
Beginning balance (deficit) (in shares) at Dec. 31, 2017				22,542,672	22,542,672
Accounting Standards Update Extensible List										us-gaap:AccountingStandardsUpdate201802Member			us-gaap:AccountingStandardsUpdate201802Member
Net (loss) income	56.4										53.2					3.2
Foreign currency translation gain (loss)	(0.6)							(0.6)
Issuance of stock grants	0.7					0.7
Issuance of stock grants (in shares)				20,757
Issuance of restricted stock units	0.0
Issuance of restricted stock units (in shares)				161,495
Issuance of performance stock units	0.0
Issuance of performance stock units (in shares)				59,052
Non-cash stock-based compensation	2.4					2.4
Distributions to noncontrolling interest	(3.3)															(3.3)
Ending balance (deficit) at Dec. 31, 2018	368.6					257.7		(2.4)			120.7			(7.5)		0.1
Ending balance (deficit) (in shares) at Dec. 31, 2018				22,783,976
Net (loss) income	51.7										48.8					2.9
Foreign currency translation gain (loss)	0.1							0.1
Change in fair value of interest rate collars	(0.4)							(0.4)
Issuance of stock grants	0.8					0.8
Issuance of stock grants (in shares)				14,076
Issuance of restricted stock units	0.0
Issuance of restricted stock units (in shares)				90,214
Issuance of performance stock units	0.0
Issuance of performance stock units (in shares)				62,094
Non-cash stock-based compensation	4.1					4.1
Repurchases of common stock	(47.8)													(47.9)
Distributions to noncontrolling interest	(3.2)															(3.2)
Ending balance (deficit) at Dec. 31, 2019	$ 373.9					262.6		(2.7)			169.5			(55.3)		(0.2)
Ending balance (deficit) (in shares) at Dec. 31, 2019	22,950,360			22,950,360
Net (loss) income	$ (172.9)										(172.8)					(0.1)
Foreign currency translation gain (loss)	0.1							0.1
Change in fair value of interest rate collars	(1.8)							(1.8)
Issuance of stock grants	0.5					0.5
Issuance of stock grants (in shares)				25,066
Issuance of restricted stock units	0.0
Issuance of restricted stock units (in shares)				66,259
Issuance of performance stock units	0.0
Issuance of performance stock units (in shares)				46,701
Noncontrolling interest buyout	(1.7)					(1.7)
Repurchases of common stock	(15.3)													(15.3)
Distributions to noncontrolling interest	(1.4)															(1.4)
Ending balance (deficit) at Dec. 31, 2020	$ 181.4					$ 261.4		$ (4.4)			$ (3.3)			$ (70.6)		$ (1.7)
Ending balance (deficit) (in shares) at Dec. 31, 2020	23,088,386			23,088,386