TOTAL EQUITY - Summary of Changes in Total Equity (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Change in Stockholders' Equity
Balances at the beginning of the period			$ 814,981
Balance at the beginning of the period (in shares)			30,016
Walker and Dunlop net income	$ 41,112	$ 34,567	$ 77,973	$ 77,788
Net income (loss) from noncontrolling interests	(79)	$ (55)	(233)	$ (216)
Other comprehensive income (loss), net of tax			(180)
Stock-based compensation - equity classified			10,169
Issuance of common stock in connection with equity compensation plans			8,067
Repurchase and retirement of common stock			(21,457)
Cash dividends paid			(15,699)
Balances at the end of the period	$ 873,621		$ 873,621
Balance at the end of the period (in shares)	30,390		30,390
Common Stock
Change in Stockholders' Equity
Balances at the beginning of the period			$ 300
Balance at the beginning of the period (in shares)			30,016
Issuance of common stock in connection with equity compensation plans			$ 8
Issuance of common stock in connection with equity compensation plans (in shares)			809
Repurchase and retirement of common stock			$ (4)
Repurchase and retirement of common stock (in shares)			(435)
Balances at the end of the period	$ 304		$ 304
Balance at the end of the period (in shares)	30,390		30,390
Additional Paid-In Capital
Change in Stockholders' Equity
Balances at the beginning of the period			$ 229,080
Stock-based compensation - equity classified			10,169
Issuance of common stock in connection with equity compensation plans			8,059
Repurchase and retirement of common stock			(12,744)
Balances at the end of the period	$ 234,564		234,564
AOCI
Change in Stockholders' Equity
Balances at the beginning of the period			93
Other comprehensive income (loss), net of tax			(180)
Balances at the end of the period	(87)		(87)
Retained Earnings
Change in Stockholders' Equity
Balances at the beginning of the period			579,943
Walker and Dunlop net income			77,973
Repurchase and retirement of common stock			(8,709)
Cash dividends paid			(15,699)
Balances at the end of the period	633,508		633,508
Noncontrolling Interests
Change in Stockholders' Equity
Balances at the beginning of the period			5,565
Net income (loss) from noncontrolling interests			(233)
Balances at the end of the period	$ 5,332		$ 5,332