Quarterly Results (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Unaudited selected financial data and operating information
Gains from mortgage banking activities	$ 76,986	$ 70,810	$ 69,950	$ 72,720	$ 71,876	$ 63,280	$ 52,241	$ 34,586	$ 290,466	$ 221,983	$ 203,671
Servicing fees	30,530	29,328	28,058	26,841	26,073	25,036	23,962	23,343	114,757	98,414	90,215
Total revenues	121,365	120,786	113,926	112,121	112,598	98,055	85,286	64,833	468,198	360,772	319,039
Personnel	49,224	49,328	45,993	40,045	48,867	41,919	34,053	24,535	184,590	149,374	133,667
Amortization and depreciation	24,385	25,644	23,470	24,674	22,764	19,818	19,097	18,459	98,173	80,138	75,955
Total expenses	87,493	87,340	81,284	76,715	86,021	73,561	64,355	52,923	332,832	276,860	252,252
Operating income	33,872	33,446	32,642	35,406	26,577	24,494	20,931	11,910	135,366	83,912	66,787
Walker & Dunlop net income	$ 20,411	$ 20,251	$ 20,153	$ 21,313	$ 16,251	$ 15,113	$ 12,914	$ 7,144	$ 82,128	$ 51,422	$ 41,530
Diluted earnings per share	$ 0.67	$ 0.66	$ 0.67	$ 0.66	$ 0.50	$ 0.47	$ 0.40	$ 0.21	$ 2.65	$ 1.58	$ 1.21
Total originations	$ 4,686,283	$ 4,936,762	$ 3,787,305	$ 4,348,398	$ 4,275,451	$ 3,124,265	$ 2,385,414	$ 1,582,576
Servicing portfolio	$ 50,212,264	$ 47,794,561	$ 47,713,739	$ 46,066,660	$ 44,031,890	$ 41,219,196	$ 39,793,733	$ 38,908,865	$ 50,212,264	$ 44,031,890	$ 38,937,027

The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.21)
-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

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-Name Accounting Standards Codification
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Reference 4: http://www.xbrl.org/2003/role/presentationRef
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-Name Regulation S-X (SX)
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-Name Regulation S-X (SX)
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Income from mortgage banking activities (fees and commissions) and servicing real estate mortgages, credit cards, and other financial assets held by others net of any related impairment of capitalized service costs. Also includes any premiums received in lieu of regular servicing fees on such loans only as earned over the life of the loans.

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Sum of operating profit and nonoperating income or expense before Income or Loss from equity method investments, income taxes, extraordinary items, and noncontrolling interest.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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The aggregate amount of expenditures for salaries, wages, profit sharing and incentive compensation, and other employee benefits, including equity-based compensation, and pension and other postretirement benefit expense.

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Net income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period).

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Generally recurring costs associated with normal operations except for the portion of these expenses which can be clearly related to production and included in cost of sales or services. Includes selling, general and administrative expense.

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This is the sum of principal amount outstanding for both securitized and unsecuritized loans of all types.

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-Publisher FASB
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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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Amount of revenue from servicing real estate mortgages, credit cards, and other financial assets held by others. Includes premiums received in lieu of regular servicing fees.

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-Publisher FASB
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Represents the amount associated with loan origination (the process when securing a mortgage for a piece of real property) or lease origination.

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