Fair Value Measurements Cash, Cash Equivalents and Marketable Securities (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jun. 30, 2014	Mar. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
CashCashEquivalentsAndShortTermInvestmentsAmortizedCost	$ 21,141	$ 28,999
CashCashEquivalentsAndShortTermInvestmentsUnrealizedLosses	4
Cash, Cash Equivalents, and Short-term Investments	21,137	28,999
Cash Equivalents, at Carrying Value	11,001	28,999
Available-for-sale Securities, Current	10,136
Fair Value, Inputs, Level 2 [Member] | Certificates of Deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
CashCashEquivalentsAndShortTermInvestmentsAmortizedCost		9,006
Cash, Cash Equivalents, and Short-term Investments		9,006
Cash Equivalents, at Carrying Value	5,004	9,006
Fair Value, Inputs, Level 2 [Member] | Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
CashCashEquivalentsAndShortTermInvestmentsAmortizedCost	5,997	19,993
Cash, Cash Equivalents, and Short-term Investments	5,997	19,993
Cash Equivalents, at Carrying Value	5,997	19,993
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Schedule of Available-for-sale Securities [Line Items]
CashCashEquivalentsAndShortTermInvestmentsAmortizedCost	5,134
CashCashEquivalentsAndShortTermInvestmentsUnrealizedLosses	4
Cash, Cash Equivalents, and Short-term Investments	5,130
Available-for-sale Securities, Current	5,130
Certificates of Deposit [Member] | Fair Value, Inputs, Level 2 [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Current	5,006
Certificates of Deposit [Member] | Fair Value, Inputs, Level 2 [Member] | Certificates of Deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
CashCashEquivalentsAndShortTermInvestmentsAmortizedCost	10,010
Cash, Cash Equivalents, and Short-term Investments	$ 10,010