FAIR VALUE MEASUREMENTS - Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Assets [Abstract]
Marketable securities:	$ 955,802
Liabilities:
Contingent consideration	3,653	$ 0
Commercial paper
Assets [Abstract]
Marketable securities:	148,957
Corporate notes and bonds
Assets [Abstract]
Marketable securities:	179,412
U.S. Government agencies
Assets [Abstract]
Marketable securities:	287,449
U.S. Treasuries
Assets [Abstract]
Marketable securities:	339,984
Recurring \| Level 1
Assets [Abstract]
Investments in debt securities	0	0
Total assets measured at fair value	411,839	654,699
Liabilities:
Contingent consideration	0	0
Warranty obligations
Warranty obligations, current	0	0
Warranty obligations, non-current	0	0
Total warranty obligations measured at fair value	0	0
Total liabilities measured at fair value	0	0
Recurring \| Level 1 \| Commercial paper
Assets [Abstract]
Marketable securities:	0	0
Recurring \| Level 1 \| Corporate notes and bonds
Assets [Abstract]
Marketable securities:	0	0
Recurring \| Level 1 \| U.S. Government agencies
Assets [Abstract]
Marketable securities:	0	0
Recurring \| Level 1 \| U.S. Treasuries
Assets [Abstract]
Marketable securities:	0	0
Recurring \| Level 1 \| Money market funds
Assets [Abstract]
Cash and cash equivalents	411,839	654,699
Recurring \| Level 1 \| Commercial paper
Assets [Abstract]
Cash and cash equivalents	0	0
Recurring \| Level 1 \| Corporate notes and bonds
Assets [Abstract]
Cash and cash equivalents	0	0
Recurring \| Level 1 \| U.S. Treasuries
Assets [Abstract]
Cash and cash equivalents	0	0
Recurring \| Level 2
Assets [Abstract]
Investments in debt securities	0	0
Total assets measured at fair value	955,802	0
Liabilities:
Contingent consideration	0	0
Warranty obligations
Warranty obligations, current	0	0
Warranty obligations, non-current	0	0
Total warranty obligations measured at fair value	0	0
Total liabilities measured at fair value	0	0
Recurring \| Level 2 \| Commercial paper
Assets [Abstract]
Marketable securities:	34,964	0
Recurring \| Level 2 \| Corporate notes and bonds
Assets [Abstract]
Marketable securities:	171,167	0
Recurring \| Level 2 \| U.S. Government agencies
Assets [Abstract]
Marketable securities:	287,449	0
Recurring \| Level 2 \| U.S. Treasuries
Assets [Abstract]
Marketable securities:	14,997	0
Recurring \| Level 2 \| Money market funds
Assets [Abstract]
Cash and cash equivalents	0	0
Recurring \| Level 2 \| Commercial paper
Assets [Abstract]
Cash and cash equivalents	113,993	0
Recurring \| Level 2 \| Corporate notes and bonds
Assets [Abstract]
Cash and cash equivalents	8,245	0
Recurring \| Level 2 \| U.S. Treasuries
Assets [Abstract]
Cash and cash equivalents	324,987	0
Recurring \| Level 3
Assets [Abstract]
Investments in debt securities	61,153	0
Total assets measured at fair value	61,153	0
Liabilities:
Contingent consideration	3,653	0
Warranty obligations
Warranty obligations, current	12,395	8,267
Warranty obligations, non-current	32,905	20,469
Total warranty obligations measured at fair value	45,300	28,736
Total liabilities measured at fair value	48,953	28,736
Recurring \| Level 3 \| Commercial paper
Assets [Abstract]
Marketable securities:	0	0
Recurring \| Level 3 \| Corporate notes and bonds
Assets [Abstract]
Marketable securities:	0	0
Recurring \| Level 3 \| U.S. Government agencies
Assets [Abstract]
Marketable securities:	0	0
Recurring \| Level 3 \| U.S. Treasuries
Assets [Abstract]
Marketable securities:	0	0
Recurring \| Level 3 \| Money market funds
Assets [Abstract]
Cash and cash equivalents	0	0
Recurring \| Level 3 \| Commercial paper
Assets [Abstract]
Cash and cash equivalents	0	0
Recurring \| Level 3 \| Corporate notes and bonds
Assets [Abstract]
Cash and cash equivalents	0	0
Recurring \| Level 3 \| U.S. Treasuries
Assets [Abstract]
Cash and cash equivalents	$ 0	$ 0

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