Employee Incentive and Retirement Plans (Tables)

3 Months Ended

Mar. 31, 2015

Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan

Stock-based compensation expense was as follows for the periods presented:

	Three Months Ended March 31,
	2015		2014
Stock options	$	7,086	$	7,033
ESPP	479		—
RSUs	481		—
Stock issued related to acquisition	3,547		—
Total stock-based compensation expense	$	11,593	$	7,033

Schedule of Stock-Based Compensation Expense Recorded for Stock Options, Warrants and Series F Convertible Preferred Stock

This stock-based compensation expense was recorded in the consolidated statement of operations as follows:

	Three Months Ended March 31,
	2015		2014
Sales and marketing	$	1,519	$	3,502
Origination and servicing	721		358
General and administrative:
Engineering and product development	1,406		737
Other	7,947		2,436
Total stock-based compensation expense	$	11,593	$	7,033

Black-Scholes Option Pricing Model to Estimate Fair Value of Stock Options Granted

We use the Black-Scholes option pricing model to estimate the fair value of stock options granted with the following assumptions during the periods presented:

	Three Months Ended March 31,
	2015		2014
Expected dividend yield	—		—
Weighted-average assumed stock price volatility	49.9	%	54.7	%
Weighted-average risk-free rate	1.56	%	1.90	%
Weighted-average expected life (in years)	6.25		6.33

Options Activity Under Option Plan

The following table summarizes the activities for our options for the three months ended March 31, 2015:

	Number of Shares		Weighted- Average Exercise Price Per Share		Weighted-Average Remaining Contractual Life (in years)	Aggregate Intrinsic Value
Outstanding at December 31, 2014	57,386,829		$	3.15
Options granted	768,500		$	20.81
Options exercised	(531,822	)	$	1.62
Options forfeited/expired	(390,152	)	$	7.11
Outstanding at March 31, 2015	57,233,355		$	3.37	7.81	$	932,931
Vested and expected to vest at March 31, 2015	56,450,213		$	3.29	7.77	$	924,352
Exercisable at March 31, 2015	24,343,206		$	0.92	6.65	$	461,441

Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity

The following table summarizes the activities for our RSUs for the three months ended March 31, 2015:

	Number of Shares		Weighted- Average Grant Date Fair Value
Unvested at December 31, 2014	—		$	—
RSUs granted	975,763		$	20.51
RSUs vested	—		$	—
RSUs forfeited/expired	(2,746	)	$	20.51
Unvested at March 31, 2015	973,017		$	20.51
Expected to vest after March 31, 2015	796,360		$	20.51

Available for ESPP

Black-Scholes Option Pricing Model to Estimate Fair Value of Stock Options Granted

We used the following assumptions in estimating the fair value of the grant under the ESPP in December 2014, which are derived using the same methodology applied to stock option assumptions:

Expected dividend yield	—
Weighted-average assumed stock price volatility	48.2	%
Weighted-average risk-free rate	0.09	%
Weighted-average expected life (in years)	0.5