Segment Reporting (Reconciliation Of Segment (Loss) Income Before Taxes) (Details) (USD $)	3 Months Ended		12 Months Ended
	Sep. 30, 2012	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Segment Reporting [Line Items]
Segment (loss) income before taxes			$ 174,750,000	$ 233,025,000	$ 233,043,000
Extinguishment of debt (see Note J)			(15,020,000)	(1,529,000)	(6,291,000)
Equity in losses of investees			(294,000)	(107,000)	(1,173,000)
Income before taxes			159,436,000	231,389,000	225,579,000
Inventory write-down			6,136,000	12,476,000	8,722,000
Auction [Member]
Segment Reporting [Line Items]
Segment (loss) income before taxes			152,240,000	225,600,000	217,227,000
Income before taxes			152,240,000	225,600,000	217,227,000
Inventory write-down			4,203,000	4,101,000	5,622,000
Finance [Member]
Segment Reporting [Line Items]
Segment (loss) income before taxes			18,595,000	12,110,000	14,776,000
Income before taxes			18,595,000	12,110,000	14,776,000
Dealer [Member]
Segment Reporting [Line Items]
Segment (loss) income before taxes			(1,423,000)	(9,289,000)	(1,697,000)
Income before taxes			(1,423,000)	(9,289,000)	(1,697,000)
Business exit costs			1,300,000
Severance costs		500,000
Other restructuring costs	800,000
Inventory write-down			1,933,000	8,375,000	3,100,000
All Other [Member]
Segment Reporting [Line Items]
Segment (loss) income before taxes			5,338,000	4,604,000	2,737,000
Income before taxes			$ 5,338,000	$ 4,604,000	$ 2,737,000