Equity	3 Months Ended
Mar. 31, 2015
Stockholders' Equity Note [Abstract]
Equity	Equity On March 18, 2015, a dividend of $0.45 per share was paid to stockholders of record on March 4, 2015. Dividends include dividend equivalents of $1.6 million, which were paid on outstanding restricted stock units for each of the three months ended March 31, 2015 and 2014. During the three months ended March 31, 2015, 731,251 restricted stock units vested and were issued as common stock of which the Company is deemed to have repurchased 307,007 shares at an average price of $34.40 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 three months ended March 31, 2014, 822,312 restricted stock units vested and were issued as common stock of which the Company is deemed to have repurchased 323,190 shares at an average price of $52.06 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 converts 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 are achieved. The revenue target for the first tranche was achieved and on April 1, 2013, the third anniversary of the closing, and 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, were canceled and the value was transferred to additional paid in capital.

Equity

3 Months Ended

Mar. 31, 2015

Stockholders' Equity Note [Abstract]

On March 18, 2015, a dividend of $0.45 per share was paid to stockholders of record on March 4, 2015. Dividends include dividend equivalents of $1.6 million, which were paid on outstanding restricted stock units for each of the three months ended March 31, 2015 and 2014.

During the three months ended March 31, 2015, 731,251 restricted stock units vested and were issued as common stock of which the Company is deemed to have repurchased 307,007 shares at an average price of $34.40 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 three months ended March 31, 2014, 822,312 restricted stock units vested and were issued as common stock of which the Company is deemed to have repurchased 323,190 shares at an average price of $52.06 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 converts 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 are achieved. The revenue target for the first tranche was achieved and on April 1, 2013, the third anniversary of the closing, and 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, were canceled and the value was transferred to additional paid in capital.