Retirement Plans (Tables)

9 Months Ended

Sep. 30, 2018

Compensation And Retirement Disclosure [Abstract]

Components of Estimated Net Pension Plan Income

The components of the estimated net pension plan income for Donnelley Financial’s pension plans for the three and nine months ended September 30, 2018 and 2017 were as follows:  

	Three Months Ended						Nine Months Ended
	September 30,						September 30,
	2018			2017			2018			2017
Pension expense (income)
Interest cost	$	2.6		$	2.6		$	7.7		$	7.9
Expected return on assets		(4.0	)		(4.0	)		(12.0	)		(12.0	)
Amortization, net		0.6			0.6			1.9			1.6
Net pension income	$	(0.8	)	$	(0.8	)	$	(2.4	)	$	(2.5	)