Shareholders' Equity - Additional Information (Detail) - USD ($)			12 Months Ended
	Dec. 10, 2020	Sep. 29, 2020	Dec. 31, 2020	Dec. 31, 2019	May 31, 2019	Dec. 31, 2018	Jun. 30, 2008
Shareholders Equity [Line Items]
Preferred stock, shares authorized			2,500,000	2,500,000			2,500,000
Preferred stock, par value			$ 0.001	$ 0.001			$ 0.001
Preferred stock, shares issued			10,000	10,000
Common stock, shares authorized			50,000,000	50,000,000			50,000,000
Common stock, par value			$ 0.001	$ 0.001			$ 0.001
Common stock, shares issued			16,735,000	12,446,000
Common stock available for future issuance			$ 6,932,000
Shares of common stock subject to awards outstanding			305,000	558,000		513,000
Stock Options [Member]
Shareholders Equity [Line Items]
Stock-based compensation plans, number of additional shares available for future grants			807,000
Closing price per share of Digimarc common stock			$ 47.24
Common Stock [Member]
Shareholders Equity [Line Items]
Stock issuance costs		$ 190,000	$ 394,000	$ 251,000
Cash proceeds from sale of common stock		$ 36,530,000	$ 2,718,000	$ 20,349,000
Issuance of common stock			2,704,000	336,000
Sale of common stock, sales agent commissions			$ 61,000	$ 483,000
Common Stock [Member] | Stock Incentive Plan [Member]
Shareholders Equity [Line Items]
Stock-based compensation, number of shares authorized			1,000,000
Common Stock [Member] | Equity Distribution Agreement With Average Price of 16.80 [Member]
Shareholders Equity [Line Items]
Common stock price per share			$ 16.80
Issuance of common stock			162,000
Common Stock [Member] | Equity Distribution Agreement With Average Price of 60.61 [Member]
Shareholders Equity [Line Items]
Common stock price per share				$ 60.61
Issuance of common stock				336,000
Common Stock [Member] | Maximum [Member]
Shareholders Equity [Line Items]
Aggregate offering price of common stock					$ 30,000,000
Common Stock [Member] | Maximum [Member] | Stock Incentive Plan [Member]
Shareholders Equity [Line Items]
Shares of common stock subject to awards outstanding			770,000
Private Placement [Member] | Common Stock [Member]
Shareholders Equity [Line Items]
Common stock, shares issued		2,542,000
Common stock price per share		$ 14.37
Series A Preferred Stock [Member]
Shareholders Equity [Line Items]
Stock-based compensation, number of shares authorized			10,000
Series A Preferred redeemable stated fair value			$ 5.00
Series A Preferred stock dividend rights			$ 0
Series A Preferred stock undistributed earnings			$ 0
Series B convertable Preffered Stock [Member]
Shareholders Equity [Line Items]
Preferred stock, par value		$ 0.001
Preferred stock, shares issued		17,000
Proceeds from issuance of preferred stock		$ 16,970,000
Stock issuance costs		$ 82,000
Preferred stock conversion price		$ 14.37
Common stock issued upon conversion of preferred stock	1,198,000
Intrinsic value	$ 11,443,000