EARNINGS PER SHARE AND STOCKHOLDERS EQUITY - Basic and Diluted EPS (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2022	Jun. 30, 2021
Calculation of basic EPS
Walker and Dunlop net income	$ 54,286	$ 71,209	$ 56,058	$ 58,052	$ 125,495	$ 114,110
Less: dividends and undistributed earnings allocated to participating securities	1,554		1,831		3,708	3,798
Net income applicable to common stockholders	$ 52,732		$ 54,227		$ 121,787	$ 110,312
Basic weighted average shares outstanding	32,388		31,019		32,304	30,922
Basic EPS	$ 1.63		$ 1.75		$ 3.77	$ 3.57
Calculation of diluted EPS
Add: reallocation of dividends and undistributed earnings based on assumed conversion	$ 9		$ 14		$ 27	$ 34
Net income allocated to common stockholders	$ 52,741		$ 54,241		$ 121,814	$ 110,346
Add: weighted-average diluted non-participating securities	306		351		353	400
Weighted average diluted shares outstanding	32,694		31,370		32,657	31,322
Diluted EPS	$ 1.61		$ 1.73		$ 3.73	$ 3.52
Shares outstanding excluded from computation of earnings per share	136				87