Related-Party Transactions	3 Months Ended
Mar. 31, 2022
Related Party Transactions [Abstract]
Related-Party Transactions	9. RELATED‑PARTY TRANSACTIONS Aircraft Lease— On August 30, 2014, a related party, Moelis & Company Manager LLC ("Manager"), acquired an aircraft with funds received solely from its managing member (Mr. Moelis). The aircraft was used and operated by the Company pursuant to a dry lease with Manager. The terms of the dry lease were comparable to the market rates of leasing from an independent third party. Pursuant to this dry lease arrangement, the lessee is obligated to bear its share of the costs of operating the aircraft. In addition, Mr. Moelis was the other lessee of the aircraft and shared the operating and related costs of the plane in proportion to his respective use pursuant to a cost sharing and operating agreement. On July 12, 2019, the Company terminated its aircraft dry lease with Manager, the lessor, and Mr. Moelis, the other lessee (the “Old Lease”) and the related cost sharing agreement with Mr. Moelis, which were set to expire by their terms on December 31, 2019, and entered into a new dry lease with Manager, the lessor, and Mr. Moelis, the other lessee (the “New Lease”) and cost sharing agreement with Mr. Moelis, which terminate on December 31, 2022. The terms of the New Lease and new cost sharing agreement are substantially similar to the Old Lease and related cost sharing agreement. For the three months ended March 31, 2022 and 2021, the Company incurred $324 and $324 in aircraft lease costs to be paid to Manager, respectively. Promissory Notes —As of March 31, 2022, there were $119 of unsecured promissory notes from employees held by the Company (December 31, 2021: $219). Any outstanding balances are reflected in accrued and other receivables on the condensed consolidated statements of financial condition. The notes held bear fixed interest rates ranging from 3.00% to 4.00%. During each of the three months ended March 31, 2022 and 2021, the Company received $0 and $70, respectively, of principal repayments and recognized interest income of $5 and $5, respectively, on such notes, which is included in other income and expenses on the condensed consolidated statements of operations. During the three months ended March 31, 2022, the Company recognized $100 of compensation and benefits expense related to a tranche of a promissory note that will not be repaid. Services Agreement —In connection with the Company’s IPO, the Company entered into a services agreement with a related party, Moelis Asset Management LP, whereby the Company provides certain administrative services to Moelis Asset Management LP for a fee. This fee totaled $55 and $57 for the three months ended March 31, 2022 and 2021, respectively. The amount of the fee is based upon the estimated usage and related expense of all shared services between the Company and Moelis Asset Management LP during the relevant period, and will be assessed periodically by management as per the terms of the agreement. As of March 31, 2022 and December 31, 2021, the Company had no balances due to or from Moelis Asset Management LP. Affiliated SPACs and SPAC Sponsors—The Company provides office space, secretarial, administrative, and other corporate services to Atlas Crest Entities. These services are provided to the Atlas Crest Entities upon consummation of their IPOs, in each case for a fee of $10 per month. For the three months ended March 31, 2022 and 2021, these fees totaled $30 and $50, respectively. This arrangement shall continue with each Atlas Crest Entity until such Atlas Crest Entity consummates a business combination or is liquidated. As of March 31, 2022, and December 31, 2021, the Company had no balances due from the Atlas Crest Entities or their sponsors. Revenues —From time to time, the Company enters into advisory transactions with affiliated entities, such as an Atlas Crest Entity or Moelis Asset Management LP and its affiliates. The Company earned revenues associated with such transactions of $159 and $0 for the three months ended March 31, 2022 and 2021, respectively.

Related-Party Transactions

3 Months Ended

Mar. 31, 2022

RELATED‑PARTY TRANSACTIONS

Aircraft Lease— On August 30, 2014, a related party, Moelis & Company Manager LLC ("Manager"), acquired an aircraft with funds received solely from its managing member (Mr. Moelis). The aircraft was used and operated by the Company pursuant to a dry lease with Manager. The terms of the dry lease were comparable to the market rates of leasing from an independent third party. Pursuant to this dry lease arrangement, the lessee is obligated to bear its share of the costs of operating the aircraft. In addition, Mr. Moelis was the other lessee of the aircraft and shared the operating and related costs of the plane in proportion to his respective use pursuant to a cost sharing and operating agreement. On July 12, 2019, the Company terminated its aircraft dry lease with Manager, the lessor, and Mr. Moelis, the other lessee (the “Old Lease”) and the related cost sharing agreement with Mr. Moelis, which were set to expire by their terms on December 31, 2019, and entered into a new dry lease with Manager, the lessor, and Mr. Moelis, the other lessee (the “New Lease”) and cost sharing agreement with Mr. Moelis, which terminate on December 31, 2022. The terms of the New Lease and new cost sharing agreement are substantially similar to the Old Lease and related cost sharing agreement.

For the three months ended March 31, 2022 and 2021, the Company incurred $324 and $324 in aircraft lease costs to be paid to Manager, respectively.

Promissory Notes —As of March 31, 2022, there were $119 of unsecured promissory notes from employees held by the Company (December 31, 2021: $219). Any outstanding balances are reflected in accrued and other receivables on the condensed consolidated statements of financial condition. The notes held bear fixed interest rates ranging from 3.00% to 4.00%. During each of the three months ended March 31, 2022 and 2021, the Company received $0 and $70, respectively, of principal repayments and recognized interest income of $5 and $5, respectively, on such notes, which is included in other income and expenses on the condensed consolidated statements of operations. During the three months ended March 31, 2022, the Company recognized $100 of compensation and benefits expense related to a tranche of a promissory note that will not be repaid.

Services Agreement —In connection with the Company’s IPO, the Company entered into a services agreement with a related party, Moelis Asset Management LP, whereby the Company provides certain administrative services to Moelis Asset Management LP for a fee. This fee totaled $55 and $57 for the three months ended March 31, 2022 and 2021, respectively. The amount of the fee is based upon the estimated usage and related expense of all shared services between the Company and Moelis Asset Management LP during the relevant period, and will be assessed periodically by management as per the terms of the agreement. As of March 31, 2022 and December 31, 2021, the Company had no balances due to or from Moelis Asset Management LP.

Affiliated SPACs and SPAC Sponsors—The Company provides office space, secretarial, administrative, and other corporate services to Atlas Crest Entities. These services are provided to the Atlas Crest Entities upon consummation of their IPOs, in each case for a fee of $10 per month. For the three months ended March 31, 2022 and 2021, these fees totaled $30 and $50, respectively. This arrangement shall continue with each Atlas Crest Entity until such Atlas Crest Entity consummates a business combination or is liquidated. As of March 31, 2022, and December 31, 2021, the Company had no balances due from the Atlas Crest Entities or their sponsors.

Revenues —From time to time, the Company enters into advisory transactions with affiliated entities, such as an Atlas Crest Entity or Moelis Asset Management LP and its affiliates. The Company earned revenues associated with such transactions of $159 and $0 for the three months ended March 31, 2022 and 2021, respectively.