SEGMENTS - Reportable Segments (Details)	12 Months Ended
	Dec. 31, 2025 USD ($) segment $ / shares	Dec. 31, 2024 USD ($) segment $ / shares	Dec. 31, 2023 USD ($) segment $ / shares
Segments
Number of reportable segments | segment	3	3	3
Revenues
Total revenues	$ 1,234,306,000	$ 1,132,490,000	$ 1,054,440,000
Expenses
Personnel	647,809,000	559,246,000	514,290,000
Amortization and depreciation	238,682,000	237,549,000	226,752,000
Provision (benefit) for credit losses	9,586,000	10,839,000	(10,452,000)
Interest expense on corporate debt	64,715,000	69,686,000	68,476,000
Goodwill impairment	0	33,000,000	62,000,000
Fair value adjustments to contingent consideration liabilities	(8,243,000)	(50,321,000)	(62,500,000)
Indemnified and repurchased loan expenses	40,850,000	10,573,000
Asset impairments and other expenses	36,746,000	1,181,000	(607,000)
Other operating expenses	125,163,000	129,236,000	118,284,000
Total expenses	1,155,308,000	1,000,989,000	916,243,000
Income before taxes	78,998,000	131,501,000	138,197,000
Income tax expense (benefit)	22,013,000	30,543,000	35,026,000
Net income before noncontrolling interests and temporary equity holders	56,985,000	100,958,000	103,171,000
Less: net income (loss) from noncontrolling interests	(99,000)	(7,209,000)	(4,186,000)
Less: net income (loss) attributable to temporary equity holders	837,000
Walker & Dunlop net income	56,247,000	108,167,000	107,357,000
Total assets	$ 5,059,478,000	$ 4,381,993,000	$ 4,052,347,000
Diluted EPS | $ / shares	$ 1.64	$ 3.19	$ 3.18
Operating margin	6.00%	12.00%	13.00%
Loan origination and debt brokerage fees, net
Revenues
Total revenues	$ 342,149,000	$ 276,562,000	$ 234,409,000
Fair value of expected net cash flows from servicing, net of guaranty obligation
Revenues
Total revenues	179,681,000	153,593,000	141,917,000
Servicing fees
Revenues
Total revenues	337,442,000	325,644,000	311,914,000
Property sales broker fees
Revenues
Total revenues	83,519,000	60,583,000	53,966,000
Investment management fees
Revenues
Total revenues	34,629,000	36,976,000	45,381,000
Net warehouse interest income (expense)
Revenues
Total revenues	(5,490,000)	(7,033,000)	(5,633,000)
Placement fees and other interest income
Revenues
Total revenues	152,584,000	167,961,000	154,520,000
Other revenues
Revenues
Total revenues	109,792,000	118,204,000	117,966,000
Capital Markets
Expenses
Goodwill impairment		33,000,000
Servicing and Asset Management
Expenses
Goodwill impairment	0	0
Operating Segments | Capital Markets
Revenues
Total revenues	646,950,000	524,841,000	476,766,000
Expenses
Personnel	475,286,000	399,256,000	375,450,000
Amortization and depreciation	4,579,000	4,551,000	4,550,000
Interest expense on corporate debt	17,506,000	19,489,000	18,779,000
Goodwill impairment		33,000,000	62,000,000
Fair value adjustments to contingent consideration liabilities		(39,491,000)	(62,500,000)
Asset impairments and other expenses	2,742,000	460,000	(1,157,000)
Other operating expenses	21,162,000	20,284,000	21,151,000
Total expenses	521,275,000	437,549,000	418,273,000
Income before taxes	125,675,000	87,292,000	58,493,000
Income tax expense (benefit)	35,019,000	20,275,000	14,824,000
Net income before noncontrolling interests and temporary equity holders	90,656,000	67,017,000	43,669,000
Less: net income (loss) from noncontrolling interests		353,000	2,489,000
Less: net income (loss) attributable to temporary equity holders	837,000
Walker & Dunlop net income	89,819,000	66,664,000	41,180,000
Total assets	$ 2,031,815,000	$ 1,407,206,000	$ 1,193,137,000
Diluted EPS | $ / shares	$ 2.62	$ 1.97	$ 1.22
Operating margin	19.00%	17.00%	12.00%
Operating Segments | Capital Markets | Loan origination and debt brokerage fees, net
Revenues
Total revenues	$ 336,947,000	$ 271,996,000	$ 232,625,000
Operating Segments | Capital Markets | Fair value of expected net cash flows from servicing, net of guaranty obligation
Revenues
Total revenues	179,681,000	153,593,000	141,917,000
Operating Segments | Capital Markets | Property sales broker fees
Revenues
Total revenues	83,519,000	60,583,000	53,966,000
Operating Segments | Capital Markets | Net warehouse interest income (expense)
Revenues
Total revenues	(5,490,000)	(8,780,000)	(9,497,000)
Operating Segments | Capital Markets | Other revenues
Revenues
Total revenues	52,293,000	47,449,000	57,755,000
Operating Segments | Servicing and Asset Management
Revenues
Total revenues	566,564,000	591,649,000	563,843,000
Expenses
Personnel	89,552,000	83,050,000	74,407,000
Amortization and depreciation	225,640,000	226,067,000	214,978,000
Provision (benefit) for credit losses	9,586,000	10,839,000	(10,452,000)
Interest expense on corporate debt	41,345,000	43,834,000	42,489,000
Fair value adjustments to contingent consideration liabilities	(8,243,000)	(10,830,000)
Indemnified and repurchased loan expenses	40,850,000	10,573,000
Asset impairments and other expenses	28,584,000	721,000	550,000
Other operating expenses	21,398,000	31,770,000	28,032,000
Total expenses	448,712,000	396,024,000	350,004,000
Income before taxes	117,852,000	195,625,000	213,839,000
Income tax expense (benefit)	32,839,000	45,437,000	54,198,000
Net income before noncontrolling interests and temporary equity holders	85,013,000	150,188,000	159,641,000
Less: net income (loss) from noncontrolling interests	(99,000)	(7,562,000)	(6,675,000)
Walker & Dunlop net income	85,112,000	157,750,000	166,316,000
Total assets	$ 2,425,954,000	$ 2,439,986,000	$ 2,273,033,000
Diluted EPS | $ / shares	$ 2.48	$ 4.65	$ 4.93
Operating margin	21.00%	33.00%	38.00%
Operating Segments | Servicing and Asset Management | Loan origination and debt brokerage fees, net
Revenues
Total revenues	$ 5,202,000	$ 4,566,000	$ 1,784,000
Operating Segments | Servicing and Asset Management | Servicing fees
Revenues
Total revenues	337,442,000	325,644,000	311,914,000
Operating Segments | Servicing and Asset Management | Investment management fees
Revenues
Total revenues	34,629,000	36,976,000	45,381,000
Operating Segments | Servicing and Asset Management | Net warehouse interest income (expense)
Revenues
Total revenues		1,747,000	3,864,000
Operating Segments | Servicing and Asset Management | Placement fees and other interest income
Revenues
Total revenues	137,864,000	153,350,000	141,374,000
Operating Segments | Servicing and Asset Management | Other revenues
Revenues
Total revenues	51,427,000	69,366,000	59,526,000
Operating Segments | Corporate
Revenues
Total revenues	20,792,000	16,000,000	13,831,000
Expenses
Personnel	82,971,000	76,940,000	64,433,000
Amortization and depreciation	8,463,000	6,931,000	7,224,000
Interest expense on corporate debt	5,864,000	6,363,000	7,208,000
Asset impairments and other expenses	5,420,000
Other operating expenses	82,603,000	77,182,000	69,101,000
Total expenses	185,321,000	167,416,000	147,966,000
Income before taxes	(164,529,000)	(151,416,000)	(134,135,000)
Income tax expense (benefit)	(45,845,000)	(35,169,000)	(33,996,000)
Net income before noncontrolling interests and temporary equity holders	(118,684,000)	(116,247,000)	(100,139,000)
Walker & Dunlop net income	(118,684,000)	(116,247,000)	(100,139,000)
Total assets	$ 601,709,000	$ 534,801,000	$ 586,177,000
Diluted EPS | $ / shares	$ (3.46)	$ (3.43)	$ (2.97)
Operating margin	(791.00%)	(946.00%)	(970.00%)
Operating Segments | Corporate | Placement fees and other interest income
Revenues
Total revenues	$ 14,720,000	$ 14,611,000	$ 13,146,000
Operating Segments | Corporate | Other revenues
Revenues
Total revenues	$ 6,072,000	$ 1,389,000	$ 685,000