Regulatory	12 Months Ended
Dec. 31, 2018
Regulatory Capital Requirements [Abstract]
Regulatory	Note 16 — Regulatory Certain subsidiaries of the Company are subject to various regulatory requirements in the United States, the United Kingdom, Australia and certain other jurisdictions, which specify, among other requirements, minimum net capital requirements for registered broker-dealers. G&Co is subject to the SEC’s Uniform Net Capital requirements under Rule 15c3-1 (the “Rule”), which specifies, among other requirements, minimum net capital requirements for registered broker-dealers. The Rule requires G&Co to maintain a minimum net capital of the greater of $5,000 or 1/15 of aggregate indebtedness, as defined in the Rule. As of December 31, 2018 and 2017, G&Co’s net capital was $25.9 million and $5.0 million, respectively, which exceeded its requirement by $24.3 million and $4.0 million, respectively. G&Co’s aggregate indebtedness to net capital ratio was 0.9 to 1 and 3.0 to 1 at December 31, 2018 and 2017, respectively. Certain distributions and other capital withdrawals of G&Co are subject to certain notifications and restrictive provisions of the Rule. GC LP is also subject to the Rule. GCI, GCE and the European affiliate of GC LP are subject to capital requirements of the FCA. Greenhill Australia is subject to capital requirements of the ASIC. We are also subject to certain capital regulatory requirements in other jurisdictions. As of December 31, 2018 and 2017, GCI, GCE, GC LP, Greenhill Australia, and our other regulated operations were in compliance with local capital adequacy requirements. As approved by FINRA in 2018, effective as of January 1, 2019, GC LP merged with G&Co, with G&Co being the sole surviving entity. The capital requirements of G&Co did not change as a result of the merger.

Regulatory

12 Months Ended

Dec. 31, 2018

Regulatory Capital Requirements [Abstract]

Note 16 — Regulatory

Certain subsidiaries of the Company are subject to various regulatory requirements in the United States, the United Kingdom, Australia and certain other jurisdictions, which specify, among other requirements, minimum net capital requirements for registered broker-dealers.

G&Co is subject to the SEC’s Uniform Net Capital requirements under Rule 15c3-1 (the “Rule”), which specifies, among other requirements, minimum net capital requirements for registered broker-dealers. The Rule requires G&Co to maintain a minimum net capital of the greater of $5,000 or 1/15 of aggregate indebtedness, as defined in the Rule. As of December 31, 2018 and 2017, G&Co’s net capital was $25.9 million and $5.0 million, respectively, which exceeded its requirement by $24.3 million and $4.0 million, respectively. G&Co’s aggregate indebtedness to net capital ratio was 0.9 to 1 and 3.0 to 1 at December 31, 2018 and 2017, respectively. Certain distributions and other capital withdrawals of G&Co are subject to certain notifications and restrictive provisions of the Rule.

GC LP is also subject to the Rule. GCI, GCE and the European affiliate of GC LP are subject to capital requirements of the FCA. Greenhill Australia is subject to capital requirements of the ASIC. We are also subject to certain capital regulatory requirements in other jurisdictions. As of December 31, 2018 and 2017, GCI, GCE, GC LP, Greenhill Australia, and our other regulated operations were in compliance with local capital adequacy requirements.

As approved by FINRA in 2018, effective as of January 1, 2019, GC LP merged with G&Co, with G&Co being the sole surviving entity. The capital requirements of G&Co did not change as a result of the merger.