Segments (Reconciliation of Assets from Segment to Consolidated) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Total Assets	$ 5,737.5	$ 5,643.7	$ 5,384.0
Operating segments | Domestic
Segment Reporting Information [Line Items]
Total Assets	1,460.1		1,488.0
Operating segments | Import
Segment Reporting Information [Line Items]
Total Assets	1,318.5		1,224.2
Operating segments | Luxury
Segment Reporting Information [Line Items]
Total Assets	865.7		934.6
Corporate and other
Segment Reporting Information [Line Items]
Total Assets	$ 2,093.2		$ 1,737.2