Earnings Per Share (Computation Of Basic And Diluted Earnings Per Share) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	0 Months Ended	3 Months Ended								12 Months Ended
	Jun. 11, 2008	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Earnings Per Share [Abstract]
Net income		$ 74,003	$ (27,726)	$ 77,632	$ (6,114)	$ 90,753	$ (30,131)	$ 91,729	$ (22,345)	$ 117,795	$ 130,006	$ 108,292
Less: Net income attributable to participating securities										1,047	60	450
Net income attributable to Sotheby's common shareholders										116,748	129,946	107,842
Weighted average common shares outstanding (shares)		68,992	68,990	68,938	69,143	68,876	68,361	68,306	67,951	69,016	68,374	67,691
Basic earnings per share - Sotheby’s common shareholders		$ 1.07	$ (0.40)	$ 1.12	$ (0.09)	$ 1.32	$ (0.44)	$ 1.34	$ (0.33)	$ 1.69	$ 1.90	$ 1.59
Less: Net income attributable to participating securities										1,047	60	446
Net income attributable to Sotheby's common shareholders										$ 116,748	$ 129,946	$ 107,846
Convertible Notes (shares)										0	97	92
Performance share units (shares)										407	428	486
Deferred stock units (shares)										162	150	163
Stock options (shares)										21	77	95
Warrants (shares)	5,900									0	49	0
Weighted average dilutive potential common shares outstanding (shares)										590	801	836
Denominator for calculation of diluted earnings per share (shares)		69,707	68,990	69,491	69,143	69,826	68,361	68,889	67,951	69,606	69,175	68,527
Diluted earnings (loss) per share - Sotheby’s common shareholders (usd per share)		$ 1.06	$ (0.40)	$ 1.11	$ (0.09)	$ 1.30	$ (0.44)	$ 1.33	$ (0.33)	$ 1.68	$ 1.88	$ 1.57