Employee Benefit Plans Employee Benefit Plans - 401 (k) Plan (Details Textual) (401(k) Plan [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, matching contribution cost recognized	$ 1.8	$ 1.7	$ 0.4
100% on first 1% [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, employer matching contributions, percent of one dollar match for employee percentage match	100.00%
Defined contribution plan, employer matching contributions, percent of employee's pre-tax contributions	1.00%
50% up to next 5% [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, employer matching contributions, percent of one dollar match for employee percentage match	50.00%
Defined contribution plan, employer matching contributions, percent of employee's pre-tax contributions	5.00%