Earnings Per Share (Tables)
 12 Months Ended
Dec. 31, 2013
Earnings Per Share [Abstract]  
Schedule of earnings per share, basic and diluted
 
2011
 
2012
 
2013
Income (loss) from continuing operations
$
(8,464
)
 
$
(10,402
)
 
$
5,540

Basic weighted-average common shares outstanding
54,908

 
56,954

 
58,521

Assumed exercise of dilutive stock options and restricted stock
—

 
—

 
726

Diluted weighted-average common shares outstanding
54,908

 
56,954

 
59,247

Income (loss) from continuing operations:
 
 
 
 
 
Basic earnings (loss) per share
$
(0.15
)
 
$
(0.18
)
 
$
0.09

Diluted earnings (loss) per share
$
(0.15
)
 
$
(0.18
)
 
$
0.09
Outstanding equity awards not included in calculation of diluted net loss per share
Outstanding equity awards not included in the calculation of diluted net earnings (loss) per share because their effect was anti-dilutive were as follows:
 
 
December 31, 2011
 
December 31, 2012
 
December 31, 2013
 
Number of
Potential
Shares
 
Range of
Exercise Prices
 
Number of
Potential
Shares
 
Range of
Exercise Prices
 
Number of
Potential
Shares
 
Range of
Exercise Prices
Stock options
7,314,039

 
$0.47 - $16.36

 
8,952,129

 
$0.47 - $16.36

 
5,879,842

 
$1.55 - $15.15

Unvested stock awards
2,221,205

 
$
—

 
655,402

 
$
—

 
92,811

 
$
—

Warrants
1,602,489

 
$
2.40

 
1,602,489

 
$
2.40

 
1,602,489

 
$
2.40