Stock-Based Compensation (Details 4) (USD $) Share data in Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Options Outstanding
Vested and expected to vest Options Outstanding, Number Outstanding	7,981
Vested and expected to vest Options Outstanding, Weighted Average Remaining Contractual Life	3 years 9 months 22 days
Vested and expected to vest Options Outstanding, Weighted Average Exercise Price	$ 3.82
Exercisable, Number Outstanding	5,712
Exercisable, Weighted Average Remaining Contractual Life	2 years 11 months 1 day
Exercisable, Weighted Average Exercise Price	$ 3.83
Options Exercisable
Aggregate Intrinsic value (in dollars)	$ 196,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number	5,712
Exercisable, Aggregate Intrinsic Value	191,000
$1.50 - $3.10
Exercise price range
Low end of the range (in dollars per share)	$ 1.50
High end of the range (in dollars per share)	$ 3.10
Options Outstanding
Number Outstanding (in shares)	2,155
Weighted Average Remaining Contractual Life	2 years 7 months 6 days
Weighted Average Exercise Price (in dollars per share)	$ 2.48
Options Exercisable
Number Exercisable (in shares)	1,579
Weighted Average Exercise Price (in dollars per share)	$ 2.34
$3.11 - $3.85
Exercise price range
Low end of the range (in dollars per share)	$ 3.11
High end of the range (in dollars per share)	$ 3.85
Options Outstanding
Number Outstanding (in shares)	2,289
Weighted Average Remaining Contractual Life	4 years
Weighted Average Exercise Price (in dollars per share)	$ 3.52
Options Exercisable
Number Exercisable (in shares)	1,541
Weighted Average Exercise Price (in dollars per share)	$ 3.57
$3.86 - $4.46
Exercise price range
Low end of the range (in dollars per share)	$ 3.86
High end of the range (in dollars per share)	$ 4.46
Options Outstanding
Number Outstanding (in shares)	2,241
Weighted Average Remaining Contractual Life	5 years 9 months 15 days
Weighted Average Exercise Price (in dollars per share)	$ 4.28
Options Exercisable
Number Exercisable (in shares)	1,315
Weighted Average Exercise Price (in dollars per share)	$ 4.27
$4.47 - $6.50
Exercise price range
Low end of the range (in dollars per share)	$ 4.47
High end of the range (in dollars per share)	$ 6.50
Options Outstanding
Number Outstanding (in shares)	1,542
Weighted Average Remaining Contractual Life	2 years 10 months 17 days
Weighted Average Exercise Price (in dollars per share)	$ 5.47
Options Exercisable
Number Exercisable (in shares)	1,277
Weighted Average Exercise Price (in dollars per share)	$ 5.52
$1.50 - $6.50
Exercise price range
Low end of the range (in dollars per share)	$ 1.50
High end of the range (in dollars per share)	$ 6.50
Options Outstanding
Number Outstanding (in shares)	8,227
Weighted Average Remaining Contractual Life	3 years 10 months 28 days
Weighted Average Exercise Price (in dollars per share)	$ 3.82
Options Exercisable
Number Exercisable (in shares)	5,712
Weighted Average Exercise Price (in dollars per share)	$ 3.83
Aggregate Intrinsic value (in dollars)	197,000
Options
Options Exercisable
Total intrinsic value of awards exercised (in dollars)	$ 800,000	$ 1,400,000	$ 2,700,000