Cash, cash equivalents, restricted cash and amount of investment in securities measured at fair value.

No definition available.

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Cash, cash equivalents, restricted cash and amount of unrealized loss in securities measured at fair value.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
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- Definition

Cash, cash equivalents, restricted cash and amortized cost of investment in securities measured at fair value.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Represents the number of investments held.

+ References

No definition available.

+ Details

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Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the number of investments sold.

+ References

No definition available.

+ Details

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Namespace Prefix:	ntra_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

+ Details

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- Definition

Amount of cash and cash equivalents, and cash and cash equivalents restricted to withdrawal or usage. Excludes amount for disposal group and discontinued operations. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, 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.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482913/230-10-50-8

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-Topic 230
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-Name Accounting Standards Codification
-Section 45
-Paragraph 24
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-URI https://asc.fasb.org/1943274/2147482740/230-10-45-24

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-Topic 230
-SubTopic 10
-Section 45
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-4

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of allowance for credit loss on 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/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (aaa)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
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-Name Accounting Standards Codification
-Section 45
-Paragraph 1
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Subparagraph (a)
-Publisher FASB
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-Topic 326
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-Section 50
-Paragraph 9
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479106/326-30-50-9

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

The cash inflow associated with the aggregate amount received by the entity through sale or maturity of marketable securities (held-to-maturity or available-for-sale) during the period.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

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- Details

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Financial Instruments (Details) $ in Thousands	12 Months Ended
Financial Instruments (Details) $ in Thousands	Dec. 31, 2025 USD ($) item	Dec. 31, 2024 USD ($) item	Dec. 31, 2023 USD ($) item	Dec. 31, 2022 USD ($)
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Cash, cash equivalents and restricted cash	$ 1,076,140	$ 945,587	$ 642,095	$ 466,091
Proceeds from investments sold		$ 24,800
Number of investments held \| item	0
Number of investments sold \| item	0	1	0
Credit loss reserve		$ 0
Available-for-sale securities
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized Cost	$ 1,076,140	968,606
Gross Unrealized Loss		(330)
Estimated Fair Value	1,076,140	968,276
Liquid demand deposits
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized Cost	1,076,140	945,587
Estimated Fair Value	1,076,140	945,587
Municipal securities
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized Cost		23,019
Gross Unrealized Loss		(330)
Estimated Fair Value		22,689
Cash equivalents \| Available-for-sale securities
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Estimated Fair Value	$ 1,076,140	945,587
Short-term investments \| Available-for-sale securities
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Estimated Fair Value		$ 22,689