Employee Benefit Plans (Tables)

6 Months Ended

Jun. 30, 2014

Employee Benefit Plans [Abstract]

Summary Of Weighted Average Fair Value Of Stock Options Granted

	Three Months Ended June 30,				Six Months Ended June 30,
	2013		2014		2013		2014
Stock options granted (in thousands)		78		723		530		933
Weighted average fair value at date of grant	$	11.70	$	17.72	$	11.69	$	19.81

Summary Of Stock Option Activity

				Remaining	Aggregate intrinsic
		Weighted average		contractual term	value (dollars in
	Shares	exercise price		(years)	thousands)
Outstanding at December 31, 2013	2,989	$	11.80	6.55	$	142,377
Granted	933		42.11
Exercised	(376)		10.09
Forfeited	(41)		29.68
Outstanding as of June 30, 2014	3,505	$	19.84	7.17	$	101,376
Vested and expected to vest at June 30, 2014	3,389	$	19.34	7.09	$	99,639
Exercisable at June 30, 2014	2,006	$	9.48	5.62	$	77,679

Schedule Of Weighted Average Assumptions

	Three Months Ended June 30,		Six Months Ended June 30,
	2013	2014	2013	2014
Expected volatility	51.51%	47.00%	51.60%	47.08%
Risk-free interest rate	0.80%	1.86%	1.04%	1.87%
Expected term (in years)	5.34	6.08	5.95	6.07
Dividend yield	—%	—%	—%	—%

Summary Of Restricted Stock Units

		Weighted Average
		Grant Date
	Shares	Fair Value
	(in thousands)
Unvested at December 31, 2013	384	$	24.48
Granted	330		51.05
Vested	(40)		23.97
Forfeitures	(6)		23.76
Unvested at June 30, 2014	668	$	37.66

Schedule Of Stock-Based Compensation Expense

	Three Months Ended June 30,				Six Months Ended June 30,
	2013		2014		2013		2014
Cost of revenue	$	285	$	594	$	398	$	826
Technology and development		192		287		342		495
Sales and marketing		301		570		486		899
General and administrative		1,707		2,789		2,332		4,058
Total	$	2,485	$	4,240	$	3,558	$	6,278