Debt (Schedule of Original Issue Discount) (Details) $ in Millions	9 Months Ended
Sep. 30, 2019 USD ($)
Changes In Original Issue Discount [Roll Forward]
Balance at December 31, 2018	$ 1.0
Amortization of original issue discount	(0.9)
Balance at September 30, 2019	0.0
Financing Arrangement, January 2019
Changes In Original Issue Discount [Roll Forward]
Original issue discount from January 31, 2019 debt financing arrangement	15.0
Financing Arrangement, February 2017
Changes In Original Issue Discount [Roll Forward]
Loss on debt extinguishment from February 10, 2017 debt financing arrangement	(1.0)
Delayed draw Term Loan A funding and retirement of Term Loan B
Changes In Original Issue Discount [Roll Forward]
Loss on debt extinguishment from February 10, 2017 debt financing arrangement	$ (14.1)

Amount of noncash expense included in interest expense to amortize debt discount and premium associated with the related debt instruments. Excludes amortization of financing costs. Alternate captions include noncash interest expense.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28541-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.8)
-URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227

Name:	us-gaap_AmortizationOfDebtDiscountPremium
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration