Segment Reporting (Schedule Of Revenue And Income (Loss) Before Taxes by Segment) (Details) (USD $) In Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Revenues	$ 369,795	$ 281,410	$ 489,377	$ 383,289
Segment income before taxes	177,888	127,451	181,439	124,150
Auction [Member]
Revenues	353,564	269,801	463,925	365,428
Segment income before taxes	170,688	123,854	171,823	118,444
Finance [Member]
Revenues	4,401	4,565	8,686	8,741
Segment income before taxes	4,885	2,759	8,323	6,009
Dealer [Member]
Revenues	11,642	8,337	16,257	10,857
Segment income before taxes	1,508	3	(973)	(1,325)
All Other [Member]
Revenues	1,405	1,249	3,096	2,368
Segment income before taxes	1,083	890	2,363	1,396
Reconciling Items [Member]
Revenues	(1,217)	(2,542)	(2,587)	(4,105)
Segment income before taxes	$ (276)	$ (55)	$ (97)	$ (374)