Summary of Significant Accounting Policies - Summary of Cash, Cash Equivalents and Short-term Investments (Details) - USD ($) $ in Thousands |
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
|---|---|---|---|---|
| Cash and cash equivalents | ||||
| Cash | $ 46,237 | $ 48,533 | ||
| Money market accounts | 93,430 | 39,277 | ||
| Certificates of deposit | 490 | 5,041 | ||
| Corporate bonds | 2,796 | |||
| Total cash and cash equivalents | 142,953 | 92,851 | $ 66,106 | $ 56,836 |
| Marketable securities | ||||
| Marketable securities | 30,991 | 21,033 | ||
| Certificates Of Deposit | ||||
| Marketable securities | ||||
| Marketable securities | 10,516 | 10,855 | ||
| Corporate Bonds | ||||
| Marketable securities | ||||
| Marketable securities | 17,972 | $ 10,178 | ||
| Agency Mortgage-backed Securities | ||||
| Marketable securities | ||||
| Marketable securities | 2,004 | |||
| U.S. Treasury Securities | ||||
| Marketable securities | ||||
| Marketable securities | $ 499 |
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- Definition Corporate bonds at carrying value. No definition available.
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- Definition Amount of investments in debt securities classified as available-for-sale, expected to be converted to cash, sold or exchanged within one year or the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- References No definition available.
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- Definition Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition A savings certificate entitling the Entity (that is, bearer) to receive interest at an established maturity date, based upon a fixed interest rate. A certificate of deposit may be issued in any denomination. Certificates of deposit are generally issued by commercial banks and, therefore, insured by the FDIC (up to the prescribed limit). Certificates of deposit generally restrict holders from withdrawing funds on demand without the incurrence of penalties. Generally, only certificates of deposit with original maturities of three months or less qualify as cash equivalents. Original maturity means original maturity to the entity holding the investment. As a related example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three-years ago does not become a cash equivalent when its remaining maturity is three months. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- References No definition available.
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- Definition Investment in short-term money-market instruments (such as commercial paper, banker's acceptances, repurchase agreements, government securities, certificates of deposit, and so forth) which are highly liquid (that is, readily convertible to known amounts of cash) and so near their maturity that they present an insignificant risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify as cash equivalents by definition. Original maturity means an original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three-years ago does not become a cash equivalent when its remaining maturity is three months. No definition available.
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