Segments (Reconciliation of Assets from Segment to Consolidated) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Total assets	$ 4,371,593	$ 3,844,150
Operating segments | Domestic
Segment Reporting Information [Line Items]
Total assets	1,256,960	1,225,387
Operating segments | Import
Segment Reporting Information [Line Items]
Total assets	1,067,466	959,355
Operating segments | Luxury
Segment Reporting Information [Line Items]
Total assets	590,515	511,779
Corporate and other
Segment Reporting Information [Line Items]
Total assets	$ 1,456,652	$ 1,147,629