Cash, Cash Equivalents and Investments - Schedule of Company's Investments Measured at Fair Value (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013
Cash And Short Term Investments [Line Items]
Amortized Cost	$ 63,395
Total Fair Value	63,397
Corporate Bonds [Member]
Cash And Short Term Investments [Line Items]
Amortized Cost	7,743
Total Fair Value	7,732
State and Municipal Obligations [Member]
Cash And Short Term Investments [Line Items]
Amortized Cost	10,807
Total Fair Value	10,820
Cash [Member]
Cash And Short Term Investments [Line Items]
Amortized Cost	37,196
Total Fair Value	37,196
Money Market Funds [Member]
Cash And Short Term Investments [Line Items]
Amortized Cost	5,030
Total Fair Value	5,030
Certificates of Deposit [Member]
Cash And Short Term Investments [Line Items]
Amortized Cost	2,619
Total Fair Value	2,619
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Cash And Short Term Investments [Line Items]
Total Fair Value	49,958
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Corporate Bonds [Member]
Cash And Short Term Investments [Line Items]
Total Fair Value	7,732
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | State and Municipal Obligations [Member]
Cash And Short Term Investments [Line Items]
Total Fair Value
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Cash [Member]
Cash And Short Term Investments [Line Items]
Total Fair Value	37,196
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Money Market Funds [Member]
Cash And Short Term Investments [Line Items]
Total Fair Value	5,030
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Certificates of Deposit [Member]
Cash And Short Term Investments [Line Items]
Total Fair Value
Significant Other Observable Inputs (Level 2) [Member]
Cash And Short Term Investments [Line Items]
Total Fair Value	13,439
Significant Other Observable Inputs (Level 2) [Member] | Corporate Bonds [Member]
Cash And Short Term Investments [Line Items]
Total Fair Value
Significant Other Observable Inputs (Level 2) [Member] | State and Municipal Obligations [Member]
Cash And Short Term Investments [Line Items]
Total Fair Value	10,820
Significant Other Observable Inputs (Level 2) [Member] | Cash [Member]
Cash And Short Term Investments [Line Items]
Total Fair Value
Significant Other Observable Inputs (Level 2) [Member] | Money Market Funds [Member]
Cash And Short Term Investments [Line Items]
Total Fair Value
Significant Other Observable Inputs (Level 2) [Member] | Certificates of Deposit [Member]
Cash And Short Term Investments [Line Items]
Total Fair Value	2,619
Significant Unobservable Inputs (Level 3) [Member]
Cash And Short Term Investments [Line Items]
Total Fair Value
Significant Unobservable Inputs (Level 3) [Member] | Corporate Bonds [Member]
Cash And Short Term Investments [Line Items]
Total Fair Value
Significant Unobservable Inputs (Level 3) [Member] | State and Municipal Obligations [Member]
Cash And Short Term Investments [Line Items]
Total Fair Value
Significant Unobservable Inputs (Level 3) [Member] | Cash [Member]
Cash And Short Term Investments [Line Items]
Total Fair Value
Significant Unobservable Inputs (Level 3) [Member] | Money Market Funds [Member]
Cash And Short Term Investments [Line Items]
Total Fair Value
Significant Unobservable Inputs (Level 3) [Member] | Certificates of Deposit [Member]
Cash And Short Term Investments [Line Items]
Total Fair Value