Pension Plans and Other Postretirement Benefit Plans (Tables)

3 Months Ended

Mar. 31, 2018

Pension and Other Postretirement Benefits Cost (Reversal of Cost) [Abstract]

Schedule of net funded status of fully funded, underfunded, and unfunded pension plans

The following table presents the funded status of Grace’s underfunded and unfunded pension plans:

(In millions)	March 31, 2018			December 31, 2017
Underfunded defined benefit pension plans	$	(110.1	)	$	(110.5	)
Unfunded defined benefit pension plans	(405.9		)	(391.9		)
Total underfunded and unfunded defined benefit pension plans	(516.0		)	(502.4		)
Pension liabilities included in other current liabilities	(15.3		)	(15.0		)
Net funded status	$	(531.3	)	$	(517.4	)

Components of net periodic benefit cost (income)

	Three Months Ended March 31,
	2018						2017
(In millions)	U.S.			Non-U.S.			U.S.			Non-U.S.
Service cost	$	4.8		$	2.4		$	4.3		$	2.0
Interest cost	10.3			1.3			10.5			1.0
Expected return on plan assets	(14.5		)	(0.3		)	(14.4		)	(0.2		)
Amortization of prior service credit	(0.2		)	—			(0.1		)	—
Net periodic benefit cost (income)	$	0.4		$	3.4		$	0.3		$	2.8