Stock Option and Compensation Plans (Tables)

12 Months Ended

Dec. 31, 2013

Stock Option and Compensation Plans

Schedule of cash proceeds from, and the aggregate intrinsic value of, stock options exercised

	Year ended December, 31
	2013		2012		2011
Cash proceeds from options exercised	$	93	$	2	$	4
Aggregate intrinsic value of options exercised	$	4,545	$	28	$	36

Summary of the stock option activity including weighted average exercise prices, options outstanding and exercisable

	For the Year ended December 31,
	2013					2012					2011
	Common Stock Options			Weighted Average Exercise Price		Common Stock Options			Weighted Average Exercise Price		Common Stock Options			Weighted Average Exercise Price
Outstanding at beginning of year:		1,344		$	1.65		1,113		$	1.30		953		$	1.20
Granted		1,583		$	14.82		250		$	3.12		184		$	1.65
Exercised		(151	)	$	0.61		(19	)	$	0.12		(24	)	$	0.17
Expired or forfeited		(68	)	$	1.53		—			—		—			—
Outstanding at end of year:		2,708		$	9.41		1,344		$	1.65		1,113		$	1.30

	Year ended December 31,
	2013		2012		2011
Options exercisable at end of year		984		823		561
Weighted average grant date fair value (per share) of options granted during the period	$	10.48	$	1.65	$	1.18

Schedule of options outstanding and exercisable by range of exercise prices

			As of December 31, 2013
			Options Outstanding				Options Exercisable
Range of Exercise Prices	Total Options Outstanding		Weighted Average Remaining Life (Years)		Weighted Average Exercise Price		Number Exercisable		Weighted Average Exercise Price
$0.12 - $10.03		1,800		7.8	$	4.89		969	$	2.50
$10.04 - $20.00		604		9.5	$	13.37		10	$	13.22
$20.01 - $33.27		304		9.8	$	28.34		5	$	32.58
		2,708						984
Aggregate Intrinsic Value	$	62,185					$	29,107