Employee Retirement Plans (Defined Contribution Plans) (Details) - USD ($)		12 Months Ended
	Feb. 16, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Contribution Plan Disclosure [Line Items]
Employee stock ownership plan contribution	$ 22,300,000.0	$ 22,300,000	$ 0	$ 0
Quad/Graphics Diversified Plan
Defined Contribution Plan Disclosure [Line Items]
Total assets		1,800,000,000
Defined contribution plan, cost recognized		$ 8,500,000	$ 7,200,000	$ 13,300,000