| Cover | Jul. 28, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Jul. 28, 2021 |
| Entity File Number | 000-10810 |
| Entity Registrant Name | KIEWIT ROYALTY TRUST |
| Entity Central Index Key | 0000711477 |
| Entity Tax Identification Number | 47-6131402 |
| Entity Incorporation, State or Country Code | NE |
| Entity Address, Address Line One | Trust Division |
| Entity Address, Address Line Two | U.S. Bank National Association |
| Entity Address, Address Line Three | 1700 Farnam Street |
| Entity Address, City or Town | Omaha |
| Entity Address, State or Province | NE |
| Entity Address, Postal Zip Code | 68102 |
| City Area Code | 402 |
| Local Phone Number | 536-5100 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
