Stock Options And Employee Stock Purchase Plan (Narrative) (Details) (USD $)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period					5 years
Allocated Share-based Compensation Expense	$ 2,335,000	$ 2,155,000	$ 4,683,000	$ 4,448,000
Weighted-average grant date fair value of options granted			$ 0.00	$ 7.88
Number of options outstanding	1,476,068		1,476,068		1,765,461
Number of options granted			0
Cash received upon the issuance of common stock			106,000	61,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Total Intrinsic Value			4,000,000	3,200,000
Stock Options [Member]
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized	3,300,000		3,300,000		5,000,000
Restricted Stock And Restricted Stock Unit (RSU) [Member]
Allocated Share-based Compensation Expense	1,700,000	1,100,000	3,200,000	2,100,000
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized	19,300,000		19,300,000		16,000,000
Restricted Stock [Member]
Shares, Granted			170,930
Weighted-Average Grant-Date Fair Value, Granted			$ 40.08
Number of stocks outstanding	706,464		706,464		828,475
Restricted Stock Units (RSUs) [Member]
Shares, Granted			6,675
Number of stocks outstanding	80,425		80,425		115,466
1997 Stock Option Plan [Member]
Additional shares authorized for issuance			840,000
Maximum issuance of common stock	12,000,000		12,000,000
1997 Stock Option Plan [Member] | Stock Options [Member]
Number of options outstanding	635,424		635,424
1997 Stock Option Plan [Member] | Restricted Stock [Member]
Number of stocks outstanding	0		0
2007 Stock Plan [Member]
Number of options outstanding	840,644		840,644
Number of stocks outstanding	80,425		80,425
Maximum issuance of common stock	4,500,000		4,500,000
Ziff Davis, Inc. 2012 Equity Incentive Plan [Member]
Shares, Granted					13,035,000
Maximum issuance of common stock	15,000,000		15,000,000
Employee Stock Purchase Plan [Member] | Common Stock [Member]
Market value of common stock on the date of grant for incentive stock options			95.00%
Maximum earnings withheld by the employees	15.00%		15.00%
Number of shares purchased under the plan			3,158	2,432
Cash received upon the issuance of common stock			$ 106,000	$ 61,000
Number of shares available for issuance	1,642,443		1,642,443
Minimum [Member]
Market value of common stock on the date of grant for incentive stock options			85.00%