Represents the number of available for sale securities in unrealized loss positions for more than twelve months.

No definition available.

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- Definition

Represents the maturity term of securities held, which were categorized neither as trading nor held-to-maturity.

+ References

No definition available.

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- Definition

Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27161-111563

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- Definition

Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
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- Definition

This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.2)
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- Definition

This item represents the aggregate fair value of investments in debt and equity securities categorized neither as held-to-maturity nor trading securities that have been in a continuous unrealized loss position for less than twelve months.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section 25
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-Subparagraph (b)
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- Definition

Number of investment positions in available-for-sale investments in a continuous unrealized loss position for which an other-than-temporary impairment (OTTI) has not been recognized in the income statement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Paragraph 1
-Subparagraph (SX 210.5-02.1)
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Fair value portion 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.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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Marketable Securities (Details) $ in Thousands	3 Months Ended
Marketable Securities (Details) $ in Thousands	Mar. 31, 2017 USD ($) security	Dec. 31, 2016 USD ($) security	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Available-for-sale marketable securities and cash and cash equivalents
Cash and cash equivalents, Amortized Cost Value	$ 174,621	$ 258,567	$ 104,414	$ 159,678
Cash and cash equivalents, Fair Value	174,621	258,567
Marketable securities, Amortized Cost	107,452	73,808
Available-for-sale securities, gross unrealized gains	48	78
Available-for-sale securities, gross unrealized losses	(14)	(6)
Marketable securities, Fair Value	$ 107,486	$ 73,880
Debt securities held in an unrealized loss position for more than 12 months \| security	0	0
Debt securities held in an unrealized loss position for less than 12 months \| security	15	13
Fair value of debt securities in an unrealized loss position for less than 12 months	$ 50,100	$ 35,700
Marketable securities, contractual term to maturity	1 year
Domestic corporate debt securities
Available-for-sale marketable securities and cash and cash equivalents
Marketable securities, Amortized Cost	$ 37,444	19,317
Available-for-sale securities, gross unrealized gains	0	0
Available-for-sale securities, gross unrealized losses	(13)	(2)
Marketable securities, Fair Value	37,431	19,315
Domestic corporate commercial paper
Available-for-sale marketable securities and cash and cash equivalents
Marketable securities, Amortized Cost	51,859	31,852
Available-for-sale securities, gross unrealized gains	48	78
Available-for-sale securities, gross unrealized losses	0	0
Marketable securities, Fair Value	51,907	31,930
Asset-backed securities
Available-for-sale marketable securities and cash and cash equivalents
Marketable securities, Amortized Cost	18,149	22,639
Available-for-sale securities, gross unrealized gains	0	0
Available-for-sale securities, gross unrealized losses	(1)	(4)
Marketable securities, Fair Value	18,148	22,635
Cash
Available-for-sale marketable securities and cash and cash equivalents
Cash and cash equivalents, Amortized Cost Value	96,823	77,443
Cash and cash equivalents, Fair Value	96,823	77,443
Money market funds
Available-for-sale marketable securities and cash and cash equivalents
Cash and cash equivalents, Amortized Cost Value	77,798	173,631
Cash and cash equivalents, Fair Value	$ 77,798	173,631
Domestic corporate commercial paper
Available-for-sale marketable securities and cash and cash equivalents
Cash and cash equivalents, Amortized Cost Value		5,487
Cash and cash equivalents, Fair Value		5,487
Domestic corporate debt securities
Available-for-sale marketable securities and cash and cash equivalents
Cash and cash equivalents, Amortized Cost Value		2,006
Cash and cash equivalents, Fair Value		$ 2,006