Fair Value Disclosures Disclosures related to our financial assets (Details) (Fair Value, Inputs, Level 1 [Member], USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Mar. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale marketable securities	$ 17,995	$ 16,588
Adjustable Rate Government Fund [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale marketable securities	$ 17,995	$ 16,588