Equity	6 Months Ended
Jun. 30, 2015
Stockholders' Equity Note [Abstract]
Equity	Equity In connection with the acquisition of Cogent on April 1, 2015, the Company issued 779,454 shares of common stock on the acquisition date. In addition, the Company will issue 334,048 shares of common stock on the second or fourth anniversary of the Acquisition, as the case may be, if the revenue target related to the Earnout is achieved. If the revenue target related to the Earnout is not achieved the common shares will not be issued. The fair value of the contingent issuance of common shares was valued on the date of the Acquisition at $11.9 million and has been recorded as additional paid in capital in the condensed consolidated statement of financial condition. A portion of the value will be transferred to common stock if the Earnout is achieved. See "Note 3 — Acquisition" and “Note 10 — Earnings Per Share”. On June 17, 2015, a dividend of $0.45 per share was paid to stockholders of record on June 3, 2015. For the six months ended June 30, 2015 dividend payments of $0.90 per share were paid to stockholders. Dividends include dividend equivalents of $3.4 million and $3.1 million, which were paid on outstanding restricted stock units for the six months ended June 30, 2015 and 2014, respectively. During the six months ended June 30, 2015, 762,568 restricted stock units vested and were issued as common stock of which the Company is deemed to have repurchased 312,748 shares at an average price of $34.55 per share in conjunction with the payment of tax liabilities in respect of stock delivered to its employees in settlement of restricted stock units. During the six months ended June 30, 2014, 892,038 restricted stock units vested and were issued as common stock of which the Company is deemed to have repurchased 351,662 shares at an average price of $51.85 per share in conjunction with the payment of tax liabilities in respect of stock delivered to its employees in settlement of restricted stock units. In connection with the acquisition of Greenhill Australia in April 2010, the Company issued 1,099,877 shares of contingent convertible preferred stock ("Performance Stock"). The Performance Stock does not pay dividends, was issued in tranches of 659,926 shares and 439,951 shares, and would be converted to shares of the Company's common stock promptly after the third and fifth anniversaries of the closing of the acquisition, respectively, if certain separate revenue targets were achieved. The revenue target for the first tranche was achieved and, on April 1, 2013, the third anniversary of the closing, 659,926 shares of Performance Stock, which had a fair value of $32.5 million at the acquisition date, were converted to common stock. The revenue target for the second tranche was not achieved and, effective April 1, 2015, the fifth anniversary of the closing, 439,951 shares of Performance Stock, which had a fair value of $14.4 million at the acquisition date, were canceled and the value was transferred to additional paid in capital.

Equity

6 Months Ended

Jun. 30, 2015

Stockholders' Equity Note [Abstract]

In connection with the acquisition of Cogent on April 1, 2015, the Company issued 779,454 shares of common stock on the acquisition date. In addition, the Company will issue 334,048 shares of common stock on the second or fourth anniversary of the Acquisition, as the case may be, if the revenue target related to the Earnout is achieved. If the revenue target related to the Earnout is not achieved the common shares will not be issued. The fair value of the contingent issuance of common shares was valued on the date of the Acquisition at $11.9 million and has been recorded as additional paid in capital in the condensed consolidated statement of financial condition. A portion of the value will be transferred to common stock if the Earnout is achieved. See "Note 3 — Acquisition" and “Note 10 — Earnings Per Share”.

On June 17, 2015, a dividend of $0.45 per share was paid to stockholders of record on June 3, 2015. For the six months ended June 30, 2015 dividend payments of $0.90 per share were paid to stockholders. Dividends include dividend equivalents of $3.4 million and $3.1 million, which were paid on outstanding restricted stock units for the six months ended June 30, 2015 and 2014, respectively.

During the six months ended June 30, 2015, 762,568 restricted stock units vested and were issued as common stock of which the Company is deemed to have repurchased 312,748 shares at an average price of $34.55 per share in conjunction with the payment of tax liabilities in respect of stock delivered to its employees in settlement of restricted stock units.

During the six months ended June 30, 2014, 892,038 restricted stock units vested and were issued as common stock of which the Company is deemed to have repurchased 351,662 shares at an average price of $51.85 per share in conjunction with the payment of tax liabilities in respect of stock delivered to its employees in settlement of restricted stock units.

In connection with the acquisition of Greenhill Australia in April 2010, the Company issued 1,099,877 shares of contingent convertible preferred stock ("Performance Stock"). The Performance Stock does not pay dividends, was issued in tranches of 659,926 shares and 439,951 shares, and would be converted to shares of the Company's common stock promptly after the third and fifth anniversaries of the closing of the acquisition, respectively, if certain separate revenue targets were achieved. The revenue target for the first tranche was achieved and, on April 1, 2013, the third anniversary of the closing, 659,926 shares of Performance Stock, which had a fair value of $32.5 million at the acquisition date, were converted to common stock. The revenue target for the second tranche was not achieved and, effective April 1, 2015, the fifth anniversary of the closing, 439,951 shares of Performance Stock, which had a fair value of $14.4 million at the acquisition date, were canceled and the value was transferred to additional paid in capital.