Business Combination and Related Transactions (Details) - USD ($)		3 Months Ended	9 Months Ended
	Sep. 29, 2020	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Business Acquisition [Line Items]
Goodwill			$ 1,189,000		$ 1,189,000
Proceeds from warrant exercises, net of issuance costs of $52	$ 1,800,000		0	$ 1,801,000
Repurchase of common stock (in shares)	175,744
Transaction cost	$ 29,100,000	$ 21,902,000
Accrued transaction costs			$ 5,000,000		$ 25,057,000
Private Placement
Business Acquisition [Line Items]
Shares issued (in shares)	15,000,000
Price per share (in USD per share)	$ 10.00
Aggregate purchase price	$ 150,000,000
Graf | Pre-Combination Velodyne
Business Acquisition [Line Items]
Goodwill	0
Other intangible assets	0
Aggregate consideration transferred	1,800,000,000
Cash paid to acquire business	$ 222,100,000
Shares transferred in acquisition (in shares)	150,277,532
Share price (in USD per share)	$ 10.25
Value of shares transferred in acquisition	$ 1,540,300,000
Graf | Pre-Combination Velodyne | Earnout RSUs
Business Acquisition [Line Items]
Shares transferred in acquisition (in shares)	187,861
Service condition period	6 months
Graf | Pre-Combination Velodyne | Common Stock Issuable In Respect of Vested Equity Awards
Business Acquisition [Line Items]
Shares transferred in acquisition (in shares)	143,575,763
Graf | Pre-Combination Velodyne | Common Stock Earned Due To the Satisfaction of the Earnout Condition
Business Acquisition [Line Items]
Shares transferred in acquisition (in shares)	2,000,000
Graf | Pre-Combination Velodyne | Common Stock to Equity Holders That Did Not Opt To Have Their Respective Shares in the Pre-Closing Tender Offer
Business Acquisition [Line Items]
Shares transferred in acquisition (in shares)	4,702,304