Pension Arrangements (Assets Held In Rabbi Trust) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Assets held in rabbi trust	$ 47,926		$ 42,010
Company-owned variable life insurance
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Assets held in rabbi trust	41,861	[1]	39,489	[1]
Mutual fund investments
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Assets held in rabbi trust	$ 6,065	[2]	$ 2,521	[2]

[1] The COLI is reflected at its cash surrender value on Sotheby's balance sheet within Trust Assets Related to Deferred Compensation Liability.

[2] The mutual fund investments are classified as trading securities and reflected at their fair value on Sotheby's balance sheet within Trust Assets Related to Deferred Compensation Liability.