Shareholders' Equity - Additional Information (Detail) - USD ($)	1 Months Ended		12 Months Ended
	Nov. 30, 2017	Jun. 30, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	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
Common stock, shares authorized			50,000,000	50,000,000		50,000,000
Common stock, par value			$ 0.001	$ 0.001		$ 0.001
Shares of common stock subject to awards outstanding			513,000	515,000	421,000
Stock Options [Member]
Shareholders Equity [Line Items]
Stock-based compensation plans, number of additional shares authorized			1,628,000
Closing price per share of Digimarc common stock			$ 14.50
Vesting period for stock options and restricted stock			3 years
Restricted Stock [Member]
Shareholders Equity [Line Items]
Vesting period for stock options and restricted stock			4 years
Common Stock [Member]
Shareholders Equity [Line Items]
Issuance of common stock	331,000	500,000		831,000
Common stock price per share	$ 36.25	$ 35.55
Cash proceeds from sale of common stock	$ 12,000,000	$ 17,775,000
Stock issuance cost	$ 21,000	$ 77,000
Common Stock [Member] | Stock Incentive Plan [Member]
Shareholders Equity [Line Items]
Stock-based compensation, number of shares authorized			1,000,000
Common Stock [Member] | Stock Incentive Plan [Member] | Maximum [Member]
Shareholders Equity [Line Items]
Shares of common stock subject to awards outstanding			770,000
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