Pension Plans - Contributions (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
Mar. 29, 2019	Dec. 31, 2018
Qualified Pension Plan
Defined Benefit Plans and Other Postretirement Benefit Plans
Contributions paid-to-date		$ 30.0
SERP
Defined Benefit Plans and Other Postretirement Benefit Plans
Contributions paid-to-date	$ 0.1	$ 0.9
Expected future contributions	$ 0.4

Amount of contributions expected to be received by defined benefit plan from employer in fiscal year. Excludes contributions paid by employer in current fiscal year.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 6
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e2709-114920

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+ References

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- Definition

Amount of cash outflow for pension and other postretirement benefits. Includes, but is not limited to, employer contribution to fund plan asset and payment to retiree.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 25
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3536-108585

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