Earnings Per Share - Additional Information (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Earnings Per Share Disclosure [Line Items]
Net income attributable to XO Group Inc.	$ 3,120	$ 2,059	$ 3,138	$ 397	$ 2,546	$ 1,283	$ 2,916	$ (705)	$ 8,714	$ 6,040	$ 3,654
Total weighted-average basic shares									24,649,000	29,060,000	32,768,000
Dilutive Securities, Effect on Basic Earnings Per Share [Abstract]
Total weighted-average diluted shares									25,218,000	29,692,000	33,660,000
Net income per share attributable to XO Group Inc. common stockholders:
Basic (usd per share)	$ 0.13	$ 0.08	$ 0.13	$ 0.02	$ 0.10	$ 0.05	$ 0.10	$ (0.02)	$ 0.35	$ 0.21	$ 0.11
Diluted (usd per share)	$ 0.13	$ 0.08	$ 0.13	$ 0.02	$ 0.09	$ 0.04	$ 0.10	$ (0.02)	$ 0.35	$ 0.20	$ 0.11
Out of Money
Net income per share attributable to XO Group Inc. common stockholders:
Weighted average number of antidilutive stock options and restricted stock excluded from the calculation of earnings per share (shares)									41,397	184,300	161,119
Restricted stock
Dilutive Securities, Effect on Basic Earnings Per Share [Abstract]
Dilutive securities (shares)									444,000	491,000	507,000
Employee Stock Purchase Plan
Dilutive Securities, Effect on Basic Earnings Per Share [Abstract]
Dilutive securities (shares)									9,000	10,000	10,000
Options/warrants
Dilutive Securities, Effect on Basic Earnings Per Share [Abstract]
Dilutive securities (shares)									116,000	131,000	375,000