Impact of Reorganization Adjustments (Details) - USD ($) $ in Millions		3 Months Ended	12 Months Ended
Apr. 01, 2017	Apr. 01, 2017	Dec. 31, 2018
Fresh-Start Adjustment [Line Items]
Total pre-tax gain on plan effects, see also (j) below	$ (3,031.2)	$ 3,031.2	$ 12.8
Cancellation of Predecessor Common Stock	0.7	0.7
Cancellation of Predecessor Additional paid-in capital	$ (1,774.9)	$ (1,774.9)

Amount of fresh-start adjustment to additional paid-in capital.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 852
-SubTopic 10
-Section 55
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=84165509&loc=d3e56426-112766

Name:	us-gaap_FreshStartAdjustmentIncreaseDecreaseAdditionalPaidInCapital
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant