Current Vulnerability Due to Certain Concentrations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Concentration Risks [Abstract]
Duration of business operations in Israel (in years)	P48Y
Credit Concentration Risk [Member] | Cash and Cash Equivalents and Short-term Investments [Member] | MUFG Bank Ltd. [Member]
Concentration Risks [Abstract]
Concentration risk percentage (in hundredths)	18.50%
Credit Concentration Risk [Member] | Cash and Cash Equivalents and Short-term Investments [Member] | JPMorgan [Member]
Concentration Risks [Abstract]
Concentration risk percentage (in hundredths)	11.70%
Credit Concentration Risk [Member] | Cash and Cash Equivalents and Short-term Investments [Member] | HSBC [Member]
Concentration Risks [Abstract]
Concentration risk percentage (in hundredths)	12.50%
Geographic Concentration [Member] | Outside Of United States [Member]
Concentration Risks [Abstract]
Cash and cash equivalents and short-term investments	$ 686,284
Geographic Concentration [Member] | Cash and Cash Equivalents and Short-term Investments [Member] | United States [Member]
Concentration Risks [Abstract]
Concentration risk percentage (in hundredths)	14.90%
Geographic Concentration [Member] | Cash and Cash Equivalents and Short-term Investments [Member] | Germany [Member]
Concentration Risks [Abstract]
Concentration risk percentage (in hundredths)	20.60%
Geographic Concentration [Member] | Cash and Cash Equivalents and Short-term Investments [Member] | Other Europe [Member]
Concentration Risks [Abstract]
Concentration risk percentage (in hundredths)	2.40%
Geographic Concentration [Member] | Cash and Cash Equivalents and Short-term Investments [Member] | Israel [Member]
Concentration Risks [Abstract]
Concentration risk percentage (in hundredths)	16.40%
Geographic Concentration [Member] | Cash and Cash Equivalents and Short-term Investments [Member] | People's Republic Of China [Member]
Concentration Risks [Abstract]
Concentration risk percentage (in hundredths)	9.90%
Geographic Concentration [Member] | Cash and Cash Equivalents and Short-term Investments [Member] | Other Asia [Member]
Concentration Risks [Abstract]
Concentration risk percentage (in hundredths)	3.00%
Geographic Concentration [Member] | Cash and Cash Equivalents and Short-term Investments [Member] | Other [Member]
Concentration Risks [Abstract]
Concentration risk percentage (in hundredths)	1.40%
Geographic Concentration [Member] | Cash and Cash Equivalents and Short-term Investments [Member] | Singapore [Member]
Concentration Risks [Abstract]
Concentration risk percentage (in hundredths)	20.40%
Geographic Concentration [Member] | Cash and Cash Equivalents and Short-term Investments [Member] | The Republic of China (Taiwan) [Member]
Concentration Risks [Abstract]
Concentration risk percentage (in hundredths)	11.00%
Geographic Concentration [Member] | Revenue [Member] | Outside Of United States [Member]
Concentration Risks [Abstract]
Concentration risk percentage (in hundredths)	75.00%
Customer Concentration Risk [Member] | Revenue [Member]
Concentration Risks [Abstract]
Concentration risk percentage (in hundredths)	10.40%
Customer Concentration Risk [Member] | Accounts Receivable [Member]
Concentration Risks [Abstract]
Concentration risk percentage (in hundredths)	15.90%	16.10%