Label	Element	Value
Convertible Preferred Stock [Member]
Stock Issued During Period, Value, Conversion of Convertible Securities, Net of Adjustments	us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecuritiesNetOfAdjustments	$ (240,585,000)
Temporary Equity Issuance Costs	ntra_TemporaryEquityIssuanceCosts	$ 27,000
Stock Issued During Period, Shares, Conversion of Convertible Securities	us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities	(31,397,000)