5 CFR § 317.903 - Details.
(a) Definition. In this section, detail means the temporary assignment of an SES member to another position (within or outside of the SES) or the temporary assignment of a non-SES member to an SES position, with the expectation that the employee will return to the official position of record upon expiration of the detail. For purposes of pay and benefits, the employee continues to encumber the position from which detailed. The provisions of this section cover details within or outside of the employing agency.
(b) Time limits.
(i) A non-SES employee to an SES position that supervises other SES positions; or
(ii) An SES employee to a position at the GS-15 or equivalent level or below.
(c) SES career reserved positions. Only a career SES appointee or a career-type non-SES appointee may be detailed to a career reserved position.
(d) SES general positions. Any SES appointee or non-SES appointee may be detailed to a general position.