Discontinued Operations Chaucer Business (Narrative) (Details) - USD ($) $ in Millions			3 Months Ended
	Apr. 10, 2019	Feb. 14, 2019	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Revenues from the Chaucer business			$ 1,219.5	$ 1,091.5
Operating losses			109.8	93.3
Assets held-for-sale			103.6		$ 103.9
Liabilities held-for-sale			118.3		115.9
Assets Held-for-Sale [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Assets held-for-sale			23.6		57.4
Liabilities held-for-sale			12.0		$ 22.2
Chaucer Irish Entity[Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Proceeds from sale of businesses segment		$ 28.0
Australian Entities [Member] | Subsequent Event [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Cash proceeds to be received	$ 13.0
Chaucer [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Revenues from the Chaucer business			2.9	$ 239.4
Operating losses			$ 0.3