XML 29 R19.htm IDEA: XBRL DOCUMENT v3.19.1

Note 5 - Short-term Investments (Tables)

3 Months Ended

Mar. 31, 2019

Notes Tables

Debt Securities, Available-for-sale [Table Text Block]

		March 31, 2019
						Gross				Gross
		Amortized				Unrealized				Unrealized				Estimated
		Cost				Gains				Losses				Fair Value
U.S. treasury bills and government agency obligations		$	89,255			$	28			$	—			$	89,283
U.S. corporate debt securities			51,311				—				(1	)			51,310
Foreign corporate debt securities			5,027				11				—				5,038
U.S. commercial paper			50,176				—				—				50,176
Foreign commercial paper			69,972				—				(2	)			69,970
Total		$	265,741			$	39			$	(3	)		$	265,777

		December 31, 2018
						Gross				Gross
		Amortized				Unrealized				Unrealized				Estimated
		Cost				Gains				Losses				Fair Value
U.S. treasury bills and government agency obligations		$	59,747			$	—			$	(6	)		$	59,741
U.S. corporate debt securities			59,164				—				(77	)			59,087
Foreign corporate debt securities			5,041				5				—				5,046
U.S. commercial paper			52,800				—				—				52,800
Foreign commercial paper			123,870				—				(9	)			123,861
Total		$	300,622			$	5			$	(92	)		$	300,535

X

- Definition

Tabular disclosure of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-URI http://asc.fasb.org/topic&trid=2196928

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	nonnum:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- References

No definition available.

+ Details

Name:	us-gaap_TableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration