Investments - Summary of Gross Unrealized Losses (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months of Unrealized Losses, Estimated Fair Value	$ 15,470	$ 6,242
Less Than 12 Months of Unrealized Losses, Gross Unrealized Losses	(23)	(351)
12 Months or More of Unrealized Losses, Estimated Fair Value	475	405
12 Months or More of Unrealized Losses, Gross Unrealized Losses	(42)	(69)
Total, Estimated Fair Value	15,945	6,647
Total, Gross Unrealized Losses	(65)	(420)
U.S Treasury Securities and Agency Bonds
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months of Unrealized Losses, Estimated Fair Value	0	0
Less Than 12 Months of Unrealized Losses, Gross Unrealized Losses	0	0
12 Months or More of Unrealized Losses, Estimated Fair Value	0	0
12 Months or More of Unrealized Losses, Gross Unrealized Losses	0	0
Total, Estimated Fair Value	0	0
Total, Gross Unrealized Losses	0	0
Corporate bonds
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months of Unrealized Losses, Estimated Fair Value	878	992
Less Than 12 Months of Unrealized Losses, Gross Unrealized Losses	(6)	(2)
12 Months or More of Unrealized Losses, Estimated Fair Value	0	0
12 Months or More of Unrealized Losses, Gross Unrealized Losses	0	0
Total, Estimated Fair Value	878	992
Total, Gross Unrealized Losses	(6)	(2)
Mortgage Backed and Asset Backed Securities
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months of Unrealized Losses, Estimated Fair Value		431
Less Than 12 Months of Unrealized Losses, Gross Unrealized Losses		(16)
12 Months or More of Unrealized Losses, Estimated Fair Value		0
12 Months or More of Unrealized Losses, Gross Unrealized Losses		0
Total, Estimated Fair Value		431
Total, Gross Unrealized Losses		(16)
Mutual funds
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months of Unrealized Losses, Estimated Fair Value	14,592	4,819
Less Than 12 Months of Unrealized Losses, Gross Unrealized Losses	(17)	(333)
12 Months or More of Unrealized Losses, Estimated Fair Value	475	405
12 Months or More of Unrealized Losses, Gross Unrealized Losses	(42)	(69)
Total, Estimated Fair Value	15,067	5,224
Total, Gross Unrealized Losses	$ (59)	$ (402)