Accumulated Comprehensive Income (Loss) (Tables)

12 Months Ended

Dec. 31, 2012

Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]

Schedule Of Accumulated Other Comprehensive Income (Loss), Net Of Tax

Components of Accumulated other comprehensive income (loss) consisted of:

	Foreign Currency Translation Adjustments			Unrealized Holding Gains (Losses) on Investments		Accumulated Other Comprehensive Income (Loss)
Total accumulated comprehensive income (loss) at January 1, 2010	(1,053		)	960		(93		)
Less: Total accumulated comprehensive loss attributable to noncontrolling interest at January 1, 2010	1,351			—		1,351
Total accumulated comprehensive income attributable to SEI Investments Company at January 1, 2010	$	298		$	960	$	1,258
Total comprehensive income	2,205			379		2,584
Less: Total comprehensive income attributable to noncontrolling interest	(685		)	—		(685		)
Total comprehensive income attributable to SEI Investments Company	$	1,520		$	379	$	1,899
Total accumulated comprehensive income at December 31, 2010	1,152			1,339		2,491
Less: Total accumulated comprehensive loss attributable to noncontrolling interest at December 31, 2010	666			—		666
Total accumulated comprehensive income attributable to SEI Investments Company at December 31, 2010	$	1,818		$	1,339	$	3,157
Total comprehensive loss	(3,195		)	1,235		(1,960		)
Less: Total comprehensive loss attributable to noncontrolling interest	703			—		703
Total comprehensive loss attributable to SEI Investments Company	$	(2,492	)	$	1,235	$	(1,257	)
Total accumulated comprehensive income at December 31, 2011	(2,043		)	2,574		531
Less: Total accumulated comprehensive loss attributable to noncontrolling interest at December 31, 2011	1,369			—		1,369
Total accumulated comprehensive income attributable to SEI Investments Company at December 31, 2011	$	(674	)	$	2,574	$	1,900
Total comprehensive income	5,904			255		6,159
Less: Total comprehensive income attributable to noncontrolling interest	(1,820		)	—		(1,820		)
Total comprehensive income attributable to SEI Investments Company	$	4,084		$	255	$	4,339
Total accumulated comprehensive income at December 31, 2012	3,861			2,829		6,690
Less: Total accumulated comprehensive income attributable to noncontrolling interest at December 31, 2012	(451		)	—		(451		)
Total accumulated comprehensive income attributable to SEI Investments Company at December 31, 2012	$	3,410		$	2,829	$	6,239