Stock-Based Compensation - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended				9 Months Ended		12 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		0 Months Ended	3 Months Ended	9 Months Ended		3 Months Ended		9 Months Ended								9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Jul. 31, 2013	Jan. 31, 2013	Jul. 31, 2012	Jan. 31, 2012	Sep. 30, 2013	Sep. 30, 2012	Jul. 31, 2013	Jul. 31, 2012	Sep. 30, 2013 Stock Options	Sep. 30, 2012 Stock Options	Sep. 30, 2013 Stock Options	Sep. 30, 2012 Stock Options	Sep. 30, 2013 Restricted Stock	Sep. 30, 2012 Restricted Stock	Sep. 30, 2013 Restricted Stock	Sep. 30, 2012 Restricted Stock	Sep. 27, 2013 Restricted Stock President	Sep. 30, 2013 Performance-based Restricted Stock	Sep. 30, 2013 Performance-based Restricted Stock	Sep. 27, 2013 Performance-based Restricted Stock	Sep. 30, 2013 Options and ESPP	Sep. 30, 2012 Options and ESPP	Sep. 30, 2013 Options and ESPP	Sep. 30, 2012 Options and ESPP	Sep. 30, 2013 ESPP	Sep. 30, 2012 ESPP	Jul. 31, 2013 ESPP	Jan. 31, 2013 ESPP	Jul. 31, 2012 ESPP	Jan. 31, 2012 ESPP	Sep. 30, 2013 $4.00	Sep. 30, 2013 $12.97	Sep. 30, 2013 Employee Stock Purchase Plan 2009 ESPP
Shares
Options outstanding at December 31, 2012 (in shares)							201,000
Options granted (in shares)							150,000
Options exercised (in shares)							(69,000)	0
Options forfeited (in shares)							(1,000)
Options outstanding at September 30, 2013 (in shares)	281,000						281,000
Weighted Average Exercise Price
Options outstanding at December 31, 2012 (usd per share)							$ 3.60
Options granted (usd per share)							$ 12.97
Options exercised (usd per share)							$ 2.84
Options forfeited (usd per share)							$ 2.80
Options outstanding at September 30, 2013 (usd per share)	$ 8.79						$ 8.79
Intrinsic value of options exercised							$ 700,000
Lower Range of Exercise Price																																	$ 4.00	$ 12.97
Upper Range of Exercise Price																																	$ 4.00	$ 12.97
Number Outstanding as of September 30, 2013
Options Outstanding, Number of Outstanding as of September 30, 2013 (shares)	281,000						281,000																										131,000	150,000
Options Outstanding, Weighted Average Remaining Contractual Life (in years)							36 months 5 days																										0 months 270 days	48 months 358 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 8.79						$ 8.79																										$ 4.00	$ 12.97
Intrinsic value of rights outstanding ESPP																																			39,000
Options Exercisable, Number of Outstanding as of September 30, 2013 (shares)	131,000						131,000																										131,000
Options Exercisable, Weighted Average Remaining Contractual Life (in years)							0 months 270 days																										0 months 270 days
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 4.00						$ 4.00																										$ 4.00
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized																				33,000	33,000
Intrinsic value of stock options outstanding	1,200,000						1,200,000
Restricted Stock
Unvested as of December 31, 2012 (in shares)																	1,539,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period																	1,446,000		31,250
Vested (shares)																	(464,000)
Forfeited (shares)																	(255,000)
Unvested as of September 30, 2013 (in shares)															2,266,000		2,266,000
Weighted Average Grant Date Fair Value
Unvested, Beginning Balance (usd per share)																	$ 9.38					$ 12.97
Granted (usd per share)																	$ 9.68	$ 9.27							$ 2.24	$ 1.33
Vested (usd per share)																	$ 8.93
Forfeited (usd per share)																	$ 9.46
Unvested, Ending Balance (usd per share)															$ 9.66		$ 9.66					$ 12.97
Fair value of equity instrument other than options																	4,100,000	5,000,000							67,000	86,000
Shares of restricted stock repurchased to satisfy tax withholding obligations																	184,776	206,440
Aggregate intrinsic value of restricted shares															29,300,000		29,300,000
Total unrecognized compensation cost related to non-vested restricted shares															12,800,000		12,800,000			200,000	200,000
Total unrecognized compensation cost, weighted-average recognition period																	1 year 21 months 28 days				3 months														4 months
Shares issued under the ESPP			19,048	20,170	20,961	19,823			39,218	40,784
ESPP, purchase price (usd per share)																													$ 8.15	$ 7.11	$ 7.19	$ 7.00
Employee Stock Purchase Program Valuation Assumptions
Expected term													36 months 275 days														6 months	6 months
Risk-free rate																												0.15%
Risk-free rate, min							0.08%						1.40%
Risk-free rate, max							0.11%						1.62%
Expected volatility, min							19.86%						37.04%															9.00%
Expected volatility, max							20.34%						3.71%															29.40%
Dividend yield													0.00%														0.00%	0.00%
Compensation expense related to options and ESPP rights	1,665,000	1,964,000					4,552,000	6,434,000			4,400	0	4,400	0	1,400,000	2,000,000	4,300,000	6,400,000		200,000	200,000		22,000	7,000	59,000	20,000
xoxo:Sharebasedcompensationarranagementbysharebasedpaymentawardoptionsvestedinperiod								0
Grants in period, weighted average grant date fair value (in dollars per share)							$ 3.89
Cash received from exercise of options and ESPP																									$ 500,000	$ 300,000