Valuation And Qualifying Accounts (Details) (USD $)	3 Months Ended				12 Months Ended
	Dec. 31, 2011		Mar. 31, 2011		Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Valuation And Qualifying Accounts Disclosure [Line Items]
Reduction in valuation allowance			$ 24,500,000		$ 28,400,000
Reduction in valuation allowance as a result of acquisitions/disposals			25,100,000
Reversal of remaining valuation allowance	3,300,000
Increase (decrease) in deferred tax valuation allowance							28,800,000		500,000
Allowance For Doubtful Accounts [Member]
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period			652,000		652,000		756,000		948,000
Additions Charged to Expenses					2,324,000		1,176,000		2,127,000
Deductions					(2,017,000)		(1,280,000)		(2,319,000)
Other Adjustments					476,000
Balance at End of Period	1,435,000				1,435,000		652,000		756,000
Allowance For Sales Credits [Member]
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period			2,606,000		2,606,000		1,921,000		900,000
Additions Charged to Expenses					4,683,000		4,312,000		5,571,000
Deductions					(3,698,000)		(3,627,000)		(4,550,000)
Other Adjustments					76,000
Balance at End of Period	3,667,000				3,667,000		2,606,000		1,921,000
Deferred Tax Valuation Allowance [Member]
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period			32,637,000	[1],[2]	32,637,000	[1],[2]	3,862,000	[1],[3]	3,322,000	[3]
Additions Charged to Expenses					121,000	[2]	28,415,000	[1]	1,246,000	[3]
Deductions					(28,560,000)	[2]	(209,000)	[1]	(488,000)	[3]
Other Adjustments							569,000	[1]	(218,000)	[3]
Balance at End of Period	4,198,000	[2]			4,198,000	[2]	32,637,000	[1],[2]	3,862,000	[1],[3]
U.S. Deferred Tax Assets, Excluding Deferred Tax Liabilities Related To Indefinite-Lived Assets [Member]
Valuation And Qualifying Accounts Disclosure [Line Items]
Increase (decrease) in deferred tax valuation allowance							28,400,000
Deferred Tax Assets Related To Capital Loss Carryforwards [Member]
Valuation And Qualifying Accounts Disclosure [Line Items]
Increase (decrease) in deferred tax valuation allowance							(200,000)
Unrealizable Foreign Tax Credit Carryovers [Member]
Valuation And Qualifying Accounts Disclosure [Line Items]
Increase (decrease) in deferred tax valuation allowance							600,000		1,200,000
Deferred Tax Assets Related To Auction Rate Securities [Member]
Valuation And Qualifying Accounts Disclosure [Line Items]
Increase (decrease) in deferred tax valuation allowance									(500,000)
Deferred Tax Assets Related To State And local Net Operating Loss Carryovers [Member]
Valuation And Qualifying Accounts Disclosure [Line Items]
Increase (decrease) in deferred tax valuation allowance									$ (200,000)

[1] For the year ended December 31, 2010, the deferred tax valuation allowance was increased by $28.8 million consisting of an increase of $28.4 million due to the company being in a cumulative U.S. book loss position and posting a full valuation allowance on the net U.S. deferred tax assets excluding deferred tax liabilities related to indefinite-lived assets and an increase of $0.6 million due to an increase in unrealizable foreign tax credit carryovers, offset by a decrease of $0.2 million in deferred tax assets related to capital loss carryforwards. For further information, please refer to Note 11 in the accompanying notes to the consolidated financial statements included in this Annual Report on Form 10-K.

[2] For the year ended December 31, 2011, the deferred tax valuation allowance was reduced by $28.4 million including a $25.1 million reduction as a result of the acquisition of DealerTrack Processing Solutions Inc. and the sale of ALG, Inc. The deferred tax valuation allowance was also reduced by $3.3 million for current year activity of our deferred tax assets and liabilities positions, $0.1 million for our capital loss carryforwards, offset by a $0.1 million increase related to state and local net operating loss carryovers. We evaluated the combined enterprises past and expected future results, including the impact of the future reversal of the acquired deferred tax liabilities, and determined that the future reversal of the acquired deferred tax liabilities would provide sufficient taxable income to support realization of certain of our deferred tax assets. For further information, please refer to Note 11 in the accompanying notes to the consolidated financial statements included in this Annual Report on Form 10-K.

[3] For the year ended December 31, 2009, the deferred tax valuation allowance was increased by $0.5 million consisting of an increase of $1.2 million due to an increase in unrealizable foreign tax credit carryovers, offset by a decrease of $0.5 million due to a decrease in deferred tax assets related to auction rate securities and $0.2 million decrease related to state and local net operating loss carryovers. For further information, please refer to Note 11 in the accompanying notes to the consolidated financial statements included in this Annual Report on Form 10-K.