Investments - Summary by Type of Instruments Measured at Fair Value (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Cash, cash equivalents and available-for-sale investments measured at fair value on recurring basis	$ 106,583		$ 85,476
Level 1
Schedule of Available-for-sale Securities [Line Items]
Cash, cash equivalents and available-for-sale investments measured at fair value on recurring basis	90,740		57,625
Level 2
Schedule of Available-for-sale Securities [Line Items]
Cash, cash equivalents and available-for-sale investments measured at fair value on recurring basis	15,843		27,851
Level 3
Schedule of Available-for-sale Securities [Line Items]
Cash, cash equivalents and available-for-sale investments measured at fair value on recurring basis	0		0
Cash
Schedule of Available-for-sale Securities [Line Items]
Cash and cash equivalents measured at fair value on a recurring basis	65,867		8,529
Cash | Level 1
Schedule of Available-for-sale Securities [Line Items]
Cash and cash equivalents measured at fair value on a recurring basis	65,867		8,529
Cash | Level 2
Schedule of Available-for-sale Securities [Line Items]
Cash and cash equivalents measured at fair value on a recurring basis	0		0
Cash | Level 3
Schedule of Available-for-sale Securities [Line Items]
Cash and cash equivalents measured at fair value on a recurring basis	0		0
Cash Equivalents
Schedule of Available-for-sale Securities [Line Items]
Cash and cash equivalents measured at fair value on a recurring basis	5,672		10,536
Cash Equivalents | Level 1
Schedule of Available-for-sale Securities [Line Items]
Cash and cash equivalents measured at fair value on a recurring basis	5,672		9,508
Cash Equivalents | Level 2
Schedule of Available-for-sale Securities [Line Items]
Cash and cash equivalents measured at fair value on a recurring basis	0		1,028
Cash Equivalents | Level 3
Schedule of Available-for-sale Securities [Line Items]
Cash and cash equivalents measured at fair value on a recurring basis	0		0
U.S Treasury Securities and Agency Bonds
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	2,838		12,373
U.S Treasury Securities and Agency Bonds | Level 1
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	2,838		12,373
U.S Treasury Securities and Agency Bonds | Level 2
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	0		0
U.S Treasury Securities and Agency Bonds | Level 3
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	0		0
Corporate bonds
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	10,627		15,628
Corporate bonds | Level 1
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	0		0
Corporate bonds | Level 2
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	10,627		15,628
Corporate bonds | Level 3
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	0		0
Mortgage Backed and Asset Backed Securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	2,074	[1]	4,003	[1]
Mortgage Backed and Asset Backed Securities | Level 1
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	0		0
Mortgage Backed and Asset Backed Securities | Level 2
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	2,074		4,003
Mortgage Backed and Asset Backed Securities | Level 3
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	0		0
Closed-end bond funds
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	16,363		27,215
Closed-end bond funds | Level 1
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	16,363		27,215
Closed-end bond funds | Level 2
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	0		0
Closed-end bond funds | Level 3
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	0		0
Preferred Stock
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	3,142		7,192
Preferred Stock | Level 1
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	0		0
Preferred Stock | Level 2
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	3,142		7,192
Preferred Stock | Level 3
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	$ 0		$ 0

[1] At March 31, 2014 and 2013, approximately $1.1 million and $1.4 million of the estimated fair value presented were mortgage-backed securities, respectively.