Statement of Consolidated Stockholders' Equity - USD ($) $ in Millions		Total	Common Stock	Additional Paid In Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive (Loss) Income
Beginning balance, shares at Dec. 31, 2013			18,147,017
Beginning balance at Dec. 31, 2013		$ 1,084.2	$ 0.2	$ 1,023.1	$ 233.8	$ (152.2)	$ (20.7)
Stockholders' Equity [Roll Forward]
Net income (loss)		71.8			71.8
Other comprehensive income (loss), net of tax		(75.4)					(75.4)
Issuance of non-vested shares to employees			119,799
Issuance of common shares to directors, shares			2,969
Issuance of common shares to non-employee directors		0.2		0.2
Issuance of common shares to employees upon vesting of restricted stock units and performance shares, shares			44,895
Cancellation of employee non-vested shares, shares			(40,503)
Cancellation of shares to cover employees’ tax withholdings upon vesting of non-vested shares, shares			(33,696)
Cancellation of shares to cover employees’ tax withholdings upon vesting of non-vested shares		$ (2.4)		(2.4)
Repurchase of common stock, shares		(633,230)	(633,230)
Repurchase of common stock		$ (44.9)				(44.9)
Cash dividends on common stock		(25.4)			(25.4)
Excess tax benefit upon vesting of non-vested shares and dividend payment on unvested shares expected to vest		0.8		0.8
Amortization of unearned equity compensation		6.8		6.8
Restricted Stock Award, Forfeitures, Dividends		0.2			0.2
Ending balance, shares at Dec. 31, 2014			17,607,251
Ending balance at Dec. 31, 2014		1,015.9	$ 0.2	1,028.5	280.4	(197.1)	(96.1)
Stockholders' Equity [Roll Forward]
Net income (loss)		(236.6)			(236.6)
Other comprehensive income (loss), net of tax		64.4					64.4
Issuance of non-vested shares to employees			62,285
Issuance of common shares to directors, shares			2,436
Issuance of common shares to non-employee directors		0.2		0.2
Issuance of common shares to employees upon vesting of restricted stock units and performance shares, shares			52,106
Cancellation of employee non-vested shares, shares			(987)
Cancellation of shares to cover employees’ tax withholdings upon vesting of non-vested shares, shares			(37,009)
Cancellation of shares to cover employees’ tax withholdings upon vesting of non-vested shares		$ (2.8)		(2.8)
Repurchase of common stock, shares		(647,520)	(647,520)
Repurchase of common stock		$ (49.4)				(49.4)
Issuance of stock related to warrants, shares			1,015,185
Cash dividends on common stock		(28.1)			(28.1)
Excess tax benefit upon vesting of non-vested shares and dividend payment on unvested shares expected to vest		1.3		1.3
Amortization of unearned equity compensation		9.3		9.3
Restricted Stock Award, Forfeitures, Dividends		$ 0.2			0.2
Ending balance, shares (Before Cumulative Adjustment) at Dec. 31, 2015			18,053,747
Ending balance, shares (After Cumulative Adjustment) at Dec. 31, 2015			18,053,747
Ending balance, shares at Dec. 31, 2015		18,053,747
Ending balance (Before Cumulative Adjustment) at Dec. 31, 2015		$ 774.4	$ 0.2	1,036.5	15.9	(246.5)	(31.7)
Ending balance (After Cumulative Adjustment) at Dec. 31, 2015		775.1	$ 0.2	1,037.3	15.8	(246.5)	(31.7)
Ending balance at Dec. 31, 2015		774.4					(31.7)
Cumulative Effect of New Accounting Principle in Period of Adoption	[1]	0.7		0.8	(0.1)
Stockholders' Equity [Roll Forward]
Net income (loss)		$ 26.3
Beginning balance, shares (Before Cumulative Adjustment) at Dec. 31, 2015			18,053,747
Beginning balance, shares (After Cumulative Adjustment) at Dec. 31, 2015			18,053,747
Beginning balance, shares at Dec. 31, 2015		18,053,747
Beginning balance (Before Cumulative Adjustment) at Dec. 31, 2015		$ 774.4	$ 0.2	1,036.5	15.9	(246.5)	(31.7)
Beginning balance (After Cumulative Adjustment) at Dec. 31, 2015		775.1	$ 0.2	1,037.3	15.8	(246.5)	(31.7)
Beginning balance at Dec. 31, 2015		774.4					(31.7)
Stockholders' Equity [Roll Forward]
Net income (loss)		91.7			91.7
Other comprehensive income (loss), net of tax		(5.0)					(5.0)
Issuance of non-vested shares to employees			9,702
Issuance of common shares to directors, shares			1,474
Issuance of common shares to non-employee directors		0.1		0.1
Issuance of common shares to employees upon vesting of restricted stock units and performance shares, shares			66,810
Issuance of common shares to employees upon option exercises and vesting of restricted stock units and performance shares				1.2
Cancellation of employee non-vested shares, shares			(379)
Cancellation of shares to cover employees’ tax withholdings upon vesting of non-vested shares, shares			(36,055)
Cancellation of shares to cover employees’ tax withholdings upon vesting of non-vested shares		$ (2.9)		(2.9)
Repurchase of common stock, shares		(443,838)	(443,838)
Repurchase of common stock		$ (34.9)				(34.9)
Cash dividends on common stock		(32.4)			(32.4)
Amortization of unearned equity compensation		11.7		11.7
Restricted Stock Award, Forfeitures, Dividends		$ 0.1			0.1
Ending balance, shares at Dec. 31, 2016		17,651,461	17,651,461
Ending balance at Dec. 31, 2016		$ 804.7	$ 0.2	$ 1,047.4	$ 75.2	$ (281.4)	$ (36.7)

[1] See Note 5 and Note 8 for discussion of our adoption of ASU 2016-09 (as defined in Note 1).