Consolidated Statements of Stockholders' Equity - USD ($) $ in Millions	Total	Common Stock	Additional Paid-In Capital	Treasury Stock	Retained Earnings	Accumulated Other Comprehensive Loss
Beginning balance at Dec. 31, 2016	$ 717.1	$ 0.4	$ 97.1	$ (3.0)	$ 727.5	$ (104.9)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income (loss)	69.7				42.7	27.0
Dividends on common stock/equity awards ($2.88 per share)	(97.5)		0.2		(97.7)
Shares issued for stock units, net of shares withheld for taxes	0.0		(0.1)	0.1
Stock options exercised	0.3		0.3
Stock-based compensation	5.0		5.0
Ending balance at Dec. 31, 2017	694.6	0.4	102.5	(2.9)	672.5	(77.9)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income (loss)	(64.0)				68.8	(132.8)
Stranded tax effect from tax reform	0.0				0.2	(0.2)
Dividends on common stock/equity awards ($2.88 per share)	(97.7)		0.3		(98.0)
Stock-based compensation	7.3		7.3
Ending balance at Dec. 31, 2018	540.2	0.4	110.1	(2.9)	643.5	(210.9)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income (loss)	81.3				62.5	18.8
Dividends on common stock/equity awards ($2.88 per share)	(98.1)		0.4		(98.5)
Shares issued for stock units, net of shares withheld for taxes	(0.3)			(0.3)
Stock-based compensation	6.6		6.6
Ending balance at Dec. 31, 2019	$ 529.6	$ 0.4	$ 117.1	$ (3.2)	$ 607.4	$ (192.1)