Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Restricted Cash and Cash Equivalents Items [Line Items]
Cash	$ 85,047	$ 59,270
Cash equivalents	9,013	5,946
Cash and cash equivalents, restricted from use	4,300	4,700
Total cash and cash equivalents	$ 98,313	69,962
Distribution period (years)	7 years
Deferred compensation liability		100
Greenhill & Co. Australia Pty Limited
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents, restricted from use	$ 0	117
Letter of Credit
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents, restricted from use	$ 4,253	$ 4,629