Benefit Plans - Additional Information (Detail) - USD ($)
$ in Millions

12 Months Ended

Dec. 31, 2017

Dec. 31, 2016

Dec. 31, 2015

Mar. 31, 2017

Mar. 31, 2016

Mar. 28, 2015

Pension and other post-retirement plans

Pension plan contribution

$ 12.8

$ 10.0

Obligations and funded status

Defined accumulated benefit obligation plans

$ 656.7

$ 585.9

Expected rate of return on plan assets

4.11%

4.28%

3.65%

Pension plan assets yielded returns

12.30%

7.50%

(3.20%)

Savings plan

401(k) plan description

We have a 401(k) plan (the "401(k) plan") with an employee share ownership ("ESOP") bonus component, which covers certain union and all non-union U.S. employees who met certain age requirements. Under the 401(k) plan, eligible U.S. employees could voluntarily contribute a percentage of their eligible compensation. We matched contributions made by employees who met certain eligibility and service requirements. During 2017, 2016 and 2015, our matching contribution was 100% of eligible employee contributions for the first 1% of eligible compensation and 50% of the next 5% of eligible compensation.

In addition to the matching contribution, all employees who met certain service requirements received a discretionary ESOP contribution equal to 1.5% of annual eligible compensation.

As of January 1, 2018, the 401(k) company match contribution was changed to a dollar-for-dollar (100%) matching contribution on up to 5% of employee eligible earnings, contributed as before-tax contributions. This change will replace the ESOP component discussed above and offers the same 5% total company match.

Annual eligible compensation percentage

1.50%

Other retirement compensation

Other accrued retirement compensation

$ 62.9

$ 61.0

Maximum

Pension plans assets

Expected contribution

21.0

Minimum

Pension plans assets

Expected contribution

$ 18.0

First 1%

Savings plan

Matching contribution to eligible employee contributions

100.00%

Percent of eligible compensation

1.00%

Next 5%

Savings plan

Matching contribution to eligible employee contributions

50.00%

Percent of eligible compensation

5.00%

Flow 401(K) Plan

Savings plan

401(k) plan and ESOP combined expenses

$ 27.9

$ 27.1

$ 26.5

U.S.

Defined Benefit Plan Disclosure [Line Items]

Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate

3.39%

4.02%

4.21%

Obligations and funded status

Discount rate

4.02%

4.21%

3.63%

Foreign Plan [Member]

Defined Benefit Plan Disclosure [Line Items]

Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate

2.18%

2.00%

2.52%

Obligations and funded status

Discount rate

2.00%

2.52%

2.30%

Foreign Plan [Member] | Maximum

Obligations and funded status

Discount rate

0.50%

0.50%

0.50%

Expected rate of return on plan assets

5.50%

5.50%

6.00%

Foreign Plan [Member] | Minimum

Obligations and funded status

Discount rate

3.50%

4.00%

4.25%

Expected rate of return on plan assets

1.00%

1.00%

1.00%