Fair Value Measurements (Details) (Fair Value, Measurements, Recurring, USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Level 1 | Money market fund deposits
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market fund deposits	$ 18,276	$ 18,275
Level 2 | Money market fund deposits
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market fund deposits	0	0
Level 3 | Money market fund deposits
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market fund deposits	0	0
Total
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market fund deposits	$ 18,276	$ 18,275