Stockholders' Equity - Restricted Stock Units (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended		18 Months Ended
	Mar. 31, 2015	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Oct. 31, 2014
Class of Stock [Line Items]
Stock-based compensation expense recognized		$ 5,939	$ 4,228	$ 12,043	$ 9,426
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Weighted average remaining contractual term for the restricted stock units outstanding (in years)				1 year 2 months 10 days
Aggregate pre-tax intrinsic value of restricted stock units outstanding which includes performance based awards which are subject to milestone attainments		$ 21,200		$ 21,200
Common stock, closing price per share (USD per share)		$ 5.31		$ 5.31
Aggregate pretax intrinsic value		$ 8,800		$ 8,800
Restricted Stock Units (RSUs)
Class of Stock [Line Items]
Stock-based compensation expense recognized		$ 5,650	$ 3,936	$ 11,547	$ 8,720
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Number of Shares, Beginning balance (in shares)				4,328
Number of Shares, Awarded (in shares)				1,474
Number of Shares, Vested (in shares)				(1,462)
Number of Shares, Cancelled (in shares)				(342)
Number of Shares, Ending balance (in shares)	4,328	3,998		3,998
Performance-Based MSU
Class of Stock [Line Items]
Grants in period, fair value						$ 4,500
Value of shares expired unvested in period		$ 1,300		$ 1,300
Performance-Based MSU | Minimum
Class of Stock [Line Items]
Vesting percentage				0.00%
Performance-Based MSU | Maximum
Class of Stock [Line Items]
Vesting percentage				150.00%
Performance-Based MSU | First Vesting period
Class of Stock [Line Items]
Award performance period				2 years
Performance-Based MSU | Second Vesting Period
Class of Stock [Line Items]
Award performance period				3 years
1992 Equity Incentive Plan | Restricted Stock Units (RSUs)
Class of Stock [Line Items]
Vesting period, in years				4 years
1992 Equity Incentive Plan | Restricted Stock Units (RSUs) | First Vesting period
Class of Stock [Line Items]
Vesting percentage				25.00%
2011 Equity Incentive Plan | Restricted Stock Units (RSUs)
Class of Stock [Line Items]
Vesting period, in years				4 years
2011 Equity Incentive Plan | Restricted Stock Units (RSUs) | First Vesting period
Class of Stock [Line Items]
Vesting percentage				25.00%
FY2016 Short-Term Incentive Plan | Minimum
Class of Stock [Line Items]
Award pay out percentage				50.00%
FY2016 Short-Term Incentive Plan | Maximum
Class of Stock [Line Items]
Award pay out percentage				150.00%
Incentive Compensation Program
Class of Stock [Line Items]
Vesting period, in years	1 year
Value of program		$ 6,700		$ 6,700
Stock-based compensation expense recognized				$ 3,300