|
Stock Compensation (Tables)
|
12 Months Ended |
|
Dec. 31, 2014
|
| Stock Compensation |
|
| Summary of activity relating to the Company's options to purchase common stock |
|
|
|
Number of
Options
|
|
Weighted-Average
Price
Per Share
|
|
Weighted-Average
Remaining
Contractual
Term (Years)
|
|
Aggregate
Intrinsic
Value
|
|
|
|
|
|
|
|
|
|
|
(in thousands)
|
|
|
Outstanding at December 31, 2013
|
|
|
1,401,101
|
|
$
|
9.59
|
|
|
8.95
|
|
$
|
7,755
|
|
|
Granted
|
|
|
561,500
|
|
$
|
15.03
|
|
|
|
|
|
|
|
|
Forfeited or expired (vested and unvested)
|
|
|
(125,052
|
)
|
$
|
12.97
|
|
|
|
|
|
|
|
|
Exercised
|
|
|
(107,963
|
)
|
$
|
4.38
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Outstanding at December 31, 2014
|
|
|
1,729,586
|
|
$
|
11.44
|
|
|
8.43
|
|
$
|
50,155
|
|
|
|
|
|
|
|
|
|
|
|
|
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|
|
| Summary of information about the stock option plan |
|
|
|
Number of
Options
|
|
Weighted-Average
Price
Per Share
|
|
Weighted-Average
Remaining
Contractual
Term (Years)
|
|
Aggregate
Intrinsic
Value
|
|
|
|
|
|
|
|
|
|
|
(in thousands)
|
|
|
Vested and expected to vest at December 31, 2014
|
|
|
1,671,313
|
|
$
|
11.37
|
|
|
8.41
|
|
$
|
48,588
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Exercisable at December 31, 2014
|
|
|
752,397
|
|
$
|
6.61
|
|
|
7.58
|
|
$
|
25,452
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
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| Schedule of weighted-average assumptions used to compute the stock-based compensation costs for the stock options granted to employees and non-employees |
|
|
|
Year ended
December 31,
|
|
|
|
|
2014
|
|
2013
|
|
2012
|
|
|
Risk-free interest rate
|
|
|
1.81
|
%
|
|
1.45
|
%
|
|
0.85
|
%
|
|
Dividend yield
|
|
|
—
|
|
|
—
|
|
|
—
|
|
|
Weighted-average expected life of options (years)
|
|
|
6.32
|
|
|
6.26
|
|
|
6.25
|
|
|
Volatility
|
|
|
75
|
%
|
|
74
|
%
|
|
80
|
%
|
|