TOTAL EQUITY - Summary of Changes in Total Equity (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Change in Stockholders' Equity
Balance at the beginning of the period			$ 615,074
Balance at the beginning of the period (in shares)			29,551
Walker and Dunlop net income	$ 34,378	$ 29,628	$ 112,166	$ 77,107
Net income from noncontrolling interests	330	$ 233	114	$ 198
Stock-based compensation - equity classified			14,948
Issuance of common stock in connection with equity compensation plans			2,887
Repurchase and retirement of common stock			(28,863)
Other			6
Balance at the end of the period	$ 716,332		$ 716,332
Balance at the end of the period (in shares)	29,949		29,949
Common Stock
Change in Stockholders' Equity
Balance at the beginning of the period			$ 296
Balance at the beginning of the period (in shares)			29,551
Issuance of common stock in connection with equity compensation plans			$ 10
Issuance of common stock in connection with equity compensation plans (in shares)			1,077
Repurchase and retirement of common stock			$ (7)
Repurchase and retirement of common stock (in shares)			(679)
Balance at the end of the period	$ 299		$ 299
Balance at the end of the period (in shares)	29,949		29,949
Additional Paid-In Capital
Change in Stockholders' Equity
Balance at the beginning of the period			$ 228,889
Stock-based compensation - equity classified			14,948
Issuance of common stock in connection with equity compensation plans			2,877
Repurchase and retirement of common stock			(20,622)
Other			6
Balance at the end of the period	$ 226,098		226,098
Retained Earnings
Change in Stockholders' Equity
Balance at the beginning of the period			381,031
Walker and Dunlop net income			112,166
Repurchase and retirement of common stock			(8,234)
Balance at the end of the period	484,963		484,963
Noncontrolling Interests
Change in Stockholders' Equity
Balance at the beginning of the period			4,858
Net income from noncontrolling interests			114
Balance at the end of the period	$ 4,972		$ 4,972