Investments and Fair Value Disclosures - Summary of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) (USD $) | Jun. 30, 2014 | Dec. 31, 2013 |
In Thousands, unless otherwise specified |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | |
Total cash equivalents and certificates of deposit | $49,538 | [1] | $48,837 | [1] |
Total investments | 128,079 | | 117,004 | |
Total cash equivalents, certificates of deposit and investments | 177,617 | | 165,841 | |
Recurring | ' | | ' | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | |
Total cash equivalents and certificates of deposit | 49,538 | [1] | 48,837 | [1] |
Total investments | 128,079 | | 117,004 | |
Total cash equivalents, certificates of deposit and investments | 177,617 | | 165,841 | |
Recurring | Money market funds | ' | | ' | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | |
Total cash equivalents and certificates of deposit | 49,518 | | 48,256 | |
Recurring | Certificates of deposit | ' | | ' | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | |
Total cash equivalents and certificates of deposit | 20 | | 581 | |
Recurring | U.S. agency notes | ' | | ' | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | |
Total investments | 59,097 | | 50,540 | |
Recurring | Commercial paper | ' | | ' | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | |
Total investments | 7,990 | | 4,999 | |
Recurring | Corporate bonds | ' | | ' | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | |
Total investments | 60,992 | | 61,465 | |
Level 1 | Recurring | ' | | ' | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | |
Total cash equivalents and certificates of deposit | 49,538 | [1] | 48,837 | [1] |
Total investments | 0 | | 0 | |
Total cash equivalents, certificates of deposit and investments | 49,538 | | 48,837 | |
Level 1 | Recurring | Money market funds | ' | | ' | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | |
Total cash equivalents and certificates of deposit | 49,518 | | 48,256 | |
Level 1 | Recurring | Certificates of deposit | ' | | ' | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | |
Total cash equivalents and certificates of deposit | 20 | | 581 | |
Level 1 | Recurring | U.S. agency notes | ' | | ' | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | |
Total investments | 0 | | 0 | |
Level 1 | Recurring | Commercial paper | ' | | ' | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | |
Total investments | 0 | | 0 | |
Level 1 | Recurring | Corporate bonds | ' | | ' | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | |
Total investments | 0 | | 0 | |
Level 2 | Recurring | ' | | ' | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | |
Total cash equivalents and certificates of deposit | 0 | [1] | 0 | [1] |
Total investments | 128,079 | | 117,004 | |
Total cash equivalents, certificates of deposit and investments | 128,079 | | 117,004 | |
Level 2 | Recurring | Money market funds | ' | | ' | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | |
Total cash equivalents and certificates of deposit | 0 | | 0 | |
Level 2 | Recurring | Certificates of deposit | ' | | ' | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | |
Total cash equivalents and certificates of deposit | 0 | | 0 | |
Level 2 | Recurring | U.S. agency notes | ' | | ' | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | |
Total investments | 59,097 | | 50,540 | |
Level 2 | Recurring | Commercial paper | ' | | ' | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | |
Total investments | 7,990 | | 4,999 | |
Level 2 | Recurring | Corporate bonds | ' | | ' | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | |
Total investments | 60,992 | | 61,465 | |
Level 3 | Recurring | ' | | ' | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | |
Total cash equivalents and certificates of deposit | ' | [1] | ' | [1] |
Total investments | ' | | ' | |
Total cash equivalents, certificates of deposit and investments | ' | | ' | |
Level 3 | Recurring | Money market funds | ' | | ' | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | |
Total cash equivalents and certificates of deposit | ' | | ' | |
Level 3 | Recurring | Certificates of deposit | ' | | ' | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | |
Total cash equivalents and certificates of deposit | ' | | ' | |
Level 3 | Recurring | U.S. agency notes | ' | | ' | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | |
Total investments | ' | | ' | |
Level 3 | Recurring | Commercial paper | ' | | ' | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | |
Total investments | ' | | ' | |
Level 3 | Recurring | Corporate bonds | ' | | ' | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | |
Total investments | ' | | ' | |
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[1] | Includes an immaterial amount of restricted cash as of June 30, 2014 and $0.6 million of restricted cash as of December 31, 2013 and excludes $21.1 million and $21.6 million of operating cash balances as of June 30, 2014 and December 31, 2013, respectively. |