Earnings (Loss) Per Share Attributable to Quad/Graphics Common Shareholders (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Numerator
Net earnings (loss) attributable to Quad/Graphics common shareholders	$ 23.4	$ 19.8	$ 29.3	$ 51.9
Denominator
Basic weighted average number of common shares outstanding for all classes of common shares (in shares)	49.3	49.5	50.0	49.4
Plus: effect of dilutive equity incentive instruments (in shares)	1.8	2.0	1.8	2.2
Diluted weighted average number of common shares outstanding for all classes of common shares (in shares)	51.1	51.5	51.8	51.6
Earnings per share attributable to Quad/Graphics common shareholders
Basic (in dollars per share)	$ 0.47	$ 0.40	$ 0.59	$ 1.05
Diluted (in dollars per share)	0.46	0.38	0.57	1.01
Cash dividends paid per common share for all classes of common shares (in dollars per share)	$ 0.30	$ 0.30	$ 0.90	$ 0.90