Stockholders' Equity (Details 2) (USD $) In Thousands, except Per Share data, unless otherwise specified	6 Months Ended
	Sep. 30, 2012
Weighted Average Remaining Contractual Life and Weighted Average Per Share Exercise Price of Options Outstanding and Options Exercisable
Weighted average remaining contractual term for options outstanding	3 years 9 months 18 days
$ 1.68 - $ 7.12 [Member]
Weighted Average Remaining Contractual Life and Weighted Average Per Share Exercise Price of Options Outstanding and Options Exercisable
Range of Exercise Price, minimum	1.68
Range of Exercise Price, maximum	7.12
Number of Shares, Options Outstanding	939
Weighted average remaining contractual term for options outstanding	3 years 3 months 11 days
Weighted Average Exercise Price, Options Outstanding	6.40
Number of Shares, Options Exercisable	553
Weighted Average Exercise Price, Options Exercisable	6.03
$ 7.13 - $ 8.07 [Member]
Weighted Average Remaining Contractual Life and Weighted Average Per Share Exercise Price of Options Outstanding and Options Exercisable
Range of Exercise Price, minimum	7.13
Range of Exercise Price, maximum	8.07
Number of Shares, Options Outstanding	854
Weighted average remaining contractual term for options outstanding	4 years 22 days
Weighted Average Exercise Price, Options Outstanding	7.71
Number of Shares, Options Exercisable	816
Weighted Average Exercise Price, Options Exercisable	7.70
$ 8.08 - $ 11.86 [Member]
Weighted Average Remaining Contractual Life and Weighted Average Per Share Exercise Price of Options Outstanding and Options Exercisable
Range of Exercise Price, minimum	8.08
Range of Exercise Price, maximum	11.86
Number of Shares, Options Outstanding	938
Weighted average remaining contractual term for options outstanding	5 years 1 month 6 days
Weighted Average Exercise Price, Options Outstanding	10.34
Number of Shares, Options Exercisable	654
Weighted Average Exercise Price, Options Exercisable	10.15
$ 11.87 - $ 14.40 [Member]
Weighted Average Remaining Contractual Life and Weighted Average Per Share Exercise Price of Options Outstanding and Options Exercisable
Range of Exercise Price, minimum	11.87
Range of Exercise Price, maximum	14.40
Number of Shares, Options Outstanding	829
Weighted average remaining contractual term for options outstanding	3 years 4 months 2 days
Weighted Average Exercise Price, Options Outstanding	12.94
Number of Shares, Options Exercisable	732
Weighted Average Exercise Price, Options Exercisable	13.03
$ 14.41 - $ 24.16 [Member]
Weighted Average Remaining Contractual Life and Weighted Average Per Share Exercise Price of Options Outstanding and Options Exercisable
Range of Exercise Price, minimum	14.41
Range of Exercise Price, maximum	24.16
Number of Shares, Options Outstanding	378
Weighted average remaining contractual term for options outstanding	2 years 5 months 9 days
Weighted Average Exercise Price, Options Outstanding	18.15
Number of Shares, Options Exercisable	378
Weighted Average Exercise Price, Options Exercisable	18.15
$ 1.68 - $ 24.16 [Member]
Weighted Average Remaining Contractual Life and Weighted Average Per Share Exercise Price of Options Outstanding and Options Exercisable
Range of Exercise Price, minimum	1.68
Range of Exercise Price, maximum	24.16
Number of Shares, Options Outstanding	3,938
Weighted average remaining contractual term for options outstanding	3 years 9 months 26 days
Weighted Average Exercise Price, Options Outstanding	10.13
Number of Shares, Options Exercisable	3,133
Weighted Average Exercise Price, Options Exercisable	10.42