Income Taxes The 2017 U.S. Tax Cuts and Jobs Act (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
Sep. 30, 2017	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Foreign tax credits	$ 31.2
Provisional deferred income tax benefit due to the Tax Act		$ 104.7
Provisional tax effect of this deemed repatriation of unremitted foreign earnings		$ 62.3

Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to foreign tax credit.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32698-109319

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319

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Period Type:	duration