Fair Value Measurements (Details) - USD ($) $ in Thousands | 3 Months Ended | |
Mar. 31, 2017 | Mar. 31, 2016 | Dec. 31, 2016 |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Reclassification of amounts to earnings | $ 68 | $ 79 | |
Fair Value, Measurements, Recurring | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Cash Equivalents | 8,225 | | $ 13,634 |
Available for Sale Securities | 61,053 | | 31,743 |
Assets measured at fair value | 69,430 | | 45,377 |
Total liabilities measured at fair value | | | (38) |
Fair Value, Measurements, Recurring | Level 1 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Cash Equivalents | 5,229 | | 9,635 |
Available for Sale Securities | 0 | | 0 |
Assets measured at fair value | 5,229 | | 9,635 |
Total liabilities measured at fair value | | | 0 |
Fair Value, Measurements, Recurring | Level 2 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Cash Equivalents | 2,996 | | 3,999 |
Available for Sale Securities | 61,053 | | 31,743 |
Assets measured at fair value | 64,201 | | 35,742 |
Total liabilities measured at fair value | | | (38) |
Fair Value, Measurements, Recurring | Level 3 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Cash Equivalents | 0 | | 0 |
Available for Sale Securities | 0 | | 0 |
Assets measured at fair value | 0 | | 0 |
Total liabilities measured at fair value | | | 0 |
Fair Value, Measurements, Recurring | Money market funds | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Cash Equivalents | 5,229 | | 9,635 |
Fair Value, Measurements, Recurring | Money market funds | Level 1 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Cash Equivalents | 5,229 | | 9,635 |
Fair Value, Measurements, Recurring | Money market funds | Level 2 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Cash Equivalents | 0 | | 0 |
Fair Value, Measurements, Recurring | Money market funds | Level 3 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Cash Equivalents | 0 | | 0 |
Fair Value, Measurements, Recurring | Commercial paper | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Cash Equivalents | 2,996 | | 3,999 |
Available for Sale Securities | 15,931 | | |
Fair Value, Measurements, Recurring | Commercial paper | Level 1 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Cash Equivalents | 0 | | 0 |
Available for Sale Securities | 0 | | |
Fair Value, Measurements, Recurring | Commercial paper | Level 2 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Cash Equivalents | 2,996 | | 3,999 |
Available for Sale Securities | 15,931 | | |
Fair Value, Measurements, Recurring | Commercial paper | Level 3 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Cash Equivalents | 0 | | 0 |
Available for Sale Securities | 0 | | |
Fair Value, Measurements, Recurring | Certificates of deposit | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Available for Sale Securities | 21,097 | | 22,820 |
Fair Value, Measurements, Recurring | Certificates of deposit | Level 1 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Available for Sale Securities | 0 | | 0 |
Fair Value, Measurements, Recurring | Certificates of deposit | Level 2 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Available for Sale Securities | 21,097 | | 22,820 |
Fair Value, Measurements, Recurring | Certificates of deposit | Level 3 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Available for Sale Securities | 0 | | 0 |
Fair Value, Measurements, Recurring | Corporate bonds | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Available for Sale Securities | 15,019 | | 6,922 |
Fair Value, Measurements, Recurring | Corporate bonds | Level 1 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Available for Sale Securities | 0 | | 0 |
Fair Value, Measurements, Recurring | Corporate bonds | Level 2 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Available for Sale Securities | 15,019 | | 6,922 |
Fair Value, Measurements, Recurring | Corporate bonds | Level 3 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Available for Sale Securities | 0 | | 0 |
Fair Value, Measurements, Recurring | U.S. government bonds | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Available for Sale Securities | 9,006 | | 2,001 |
Fair Value, Measurements, Recurring | U.S. government bonds | Level 1 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Available for Sale Securities | 0 | | 0 |
Fair Value, Measurements, Recurring | U.S. government bonds | Level 2 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Available for Sale Securities | 9,006 | | 2,001 |
Fair Value, Measurements, Recurring | U.S. government bonds | Level 3 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Available for Sale Securities | 0 | | 0 |
Interest rate swap contract | Fair Value, Measurements, Recurring | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Interest rate swap contract | 152 | | |
Fair value of liability derivatives | | | (38) |
Interest rate swap contract | Fair Value, Measurements, Recurring | Level 1 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Interest rate swap contract | 0 | | |
Fair value of liability derivatives | | | 0 |
Interest rate swap contract | Fair Value, Measurements, Recurring | Level 2 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Interest rate swap contract | 152 | | |
Fair value of liability derivatives | | | (38) |
Interest rate swap contract | Fair Value, Measurements, Recurring | Level 3 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Interest rate swap contract | $ 0 | | |
Fair value of liability derivatives | | | $ 0 |