CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' DEFICIT - USD ($) $ in Millions		Common Stock		Treasury Stock at Cost	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit	Total
Balances at beginning of period at Dec. 31, 2017		$ 0.9		$ (4.8)	$ 299.9		$ (437.8)	$ (141.8)
Balances at beginning of period (in shares) at Dec. 31, 2017		88,426,742
Increase (Decrease) in Stockholders' Deficit
Impact of change in accounting policy							9.1	9.1
Stock-based compensation					4.3			4.3
Issuance of restricted stock, net (in shares)		657,992
Purchase of shares				(45.2)				(45.2)
Purchase of shares (in shares)		(4,636,669)
Other					(0.2)			(0.2)
Net income (loss)							(162.0)	(162.0)
Balances at end of period at Mar. 31, 2018		$ 0.9		(50.0)	304.0		(590.7)	(335.8)
Balances at end of period (in shares) at Mar. 31, 2018		84,448,065
Balances at beginning of period at Dec. 31, 2017		$ 0.9		(4.8)	299.9		(437.8)	(141.8)
Balances at beginning of period (in shares) at Dec. 31, 2017		88,426,742
Increase (Decrease) in Stockholders' Deficit
Net income (loss)								(137.4)
Balances at end of period at Jun. 30, 2018	[1]	$ 0.9		(62.5)	308.6	$ (0.6)	(566.1)	(319.7)
Balances at end of period (in shares) at Jun. 30, 2018	[1]	84,104,828
Balances at beginning of period at Mar. 31, 2018		$ 0.9		(50.0)	304.0		(590.7)	(335.8)
Balances at beginning of period (in shares) at Mar. 31, 2018		84,448,065
Increase (Decrease) in Stockholders' Deficit
Changes in accumulated other comprehensive loss						(0.6)		(0.6)
Stock-based compensation					4.6			4.6
Issuance of restricted stock, net (in shares)		978,896
Purchase of shares				(12.5)				(12.5)
Purchase of shares (in shares)		(1,322,133)
Net income (loss)							24.6	24.6
Balances at end of period at Jun. 30, 2018	[1]	$ 0.9		(62.5)	308.6	(0.6)	(566.1)	(319.7)
Balances at end of period (in shares) at Jun. 30, 2018	[1]	84,104,828
Balances at beginning of period at Dec. 31, 2018		$ 0.9		(78.1)	312.7	(6.5)	(519.3)	$ (290.3)
Balances at beginning of period (in shares) at Dec. 31, 2018		82,680,380						82,680,380
Increase (Decrease) in Stockholders' Deficit
Changes in accumulated other comprehensive loss						(3.1)		$ (3.1)
Stock-based compensation					2.1			2.1
Issuance of restricted stock, net (in shares)		1,702,482
Purchase of shares				(1.1)				(1.1)
Purchase of shares (in shares)		(108,937)
Net income (loss)							8.2	8.2
Balances at end of period at Mar. 31, 2019		$ 0.9		(79.2)	314.8	(9.6)	(511.1)	(284.2)
Balances at end of period (in shares) at Mar. 31, 2019		84,273,925
Balances at beginning of period at Dec. 31, 2018		$ 0.9		(78.1)	312.7	(6.5)	(519.3)	$ (290.3)
Balances at beginning of period (in shares) at Dec. 31, 2018		82,680,380						82,680,380
Increase (Decrease) in Stockholders' Deficit
Net income (loss)								$ 17.6
Balances at end of period at Jun. 30, 2019	[2]	$ 0.9		(79.5)	317.6	(18.1)	(501.7)	$ (280.8)
Balances at end of period (in shares) at Jun. 30, 2019		84,473,673	[2]					84,473,673
Balances at beginning of period at Mar. 31, 2019		$ 0.9		(79.2)	314.8	(9.6)	(511.1)	$ (284.2)
Balances at beginning of period (in shares) at Mar. 31, 2019		84,273,925
Increase (Decrease) in Stockholders' Deficit
Changes in accumulated other comprehensive loss						(8.5)		(8.5)
Stock-based compensation					2.8			2.8
Issuance of restricted stock, net (in shares)		239,903
Purchase of shares				(0.3)				(0.3)
Purchase of shares (in shares)		(40,155)
Net income (loss)							9.4	9.4
Balances at end of period at Jun. 30, 2019	[2]	$ 0.9		$ (79.5)	$ 317.6	$ (18.1)	$ (501.7)	$ (280.8)
Balances at end of period (in shares) at Jun. 30, 2019		84,473,673	[2]					84,473,673

[1] Included in outstanding shares as of March 31, 2018 and June 30, 2018 are 2,545,272 and 2,380,631, respectively, of non-vested shares of restricted stock awards granted to employees and directors.

[2] Included in outstanding shares as of March 31, 2019 and June 30, 2019 are 3,703,649 and 3,601,021, respectively, of non-vested shares of restricted stock awards granted to employees and directors.