| Document and Entity Information | Oct. 13, 2021 |
| Document Information [Line Items] | |
| Document Type | 8-K |
| Document Period End Date | Oct. 13, 2021 |
| Entity Registrant Name | Decarbonization Plus Acquisition Corporation II |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-40000 |
| Entity Tax Identification Number | 85-4197795 |
| Entity Address, Address Line One | 2744 Sand Hill Road |
| Entity Address, Address Line Two | Suite 100 |
| Entity Address, City or Town | Menlo Park |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 94025 |
| City Area Code | 212 |
| Local Phone Number | 993-0076 |
| Written Communications | true |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
| Amendment Flag | false |
| Entity Central Index Key | 0001836154 |
| Class A Common Stock [Member] | |
| Document Information [Line Items] | |
| Title of 12(b) Security | Class A common stock, par value $0.0001 per share |
| Trading Symbol | DCRN |
| Security Exchange Name | NASDAQ |
| Warrants [Member] | |
| Document Information [Line Items] | |
| Title of 12(b) Security | Warrants, exercisable for one share of Class A common stock at an exercise price of $11.50 per share |
| Trading Symbol | DCRNW |
| Security Exchange Name | NASDAQ |
| Unit [Member] | |
| Document Information [Line Items] | |
| Title of 12(b) Security | Units, each consisting of one share of Class A common stock,$0.0001 par value, and one-third of one warrant |
| Trading Symbol | DCRNU |
| Security Exchange Name | NASDAQ |
