Condensed Consolidated Statements of Stockholders' Equity (unaudited) - USD ($) $ in Thousands	Common Stock Restricted Stock Units	Common Stock 2019 Bonus Payout	Common Stock 2018 Bonus Payout	Common Stock Common Stock Offering, net	Common Stock	Additional Paid-In Capital 2019 Bonus Payout	Additional Paid-In Capital 2018 Bonus Payout	Additional Paid-In Capital Common Stock Offering, net	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit	Total Coherus Stockholder Equity (Deficit) 2018 Bonus Payout	Total Coherus Stockholder Equity (Deficit) Common Stock Offering, net	Total Coherus Stockholder Equity (Deficit)	2019 Bonus Payout	Total
Beginning Balances at Dec. 31, 2018					$ 7				$ 946,515	$ (282)	$ (984,831)			$ (38,591)
Beginning Balances, Shares at Dec. 31, 2018					68,302,681
Issuance of common stock upon exercise of stock options									825					825
Issuance of common stock upon exercise of stock options, Shares					143,523
Issuance of common stock							$ 1,350	$ 8,228				$ 1,350	$ 8,228
Issuance of common stock, Shares	22,195		109,168	761,130
Stock-based compensation expense									9,813					9,813
Cumulative translation adjustment										(136)				(136)
Net income (loss)											(20,004)			(20,004)
Ending Balances at Mar. 31, 2019					$ 7				966,731	(418)	(1,004,835)			(38,515)
Ending Balances, shares at Mar. 31, 2019					69,338,697
Beginning Balances at Dec. 31, 2018					$ 7				946,515	(282)	(984,831)			(38,591)
Beginning Balances, Shares at Dec. 31, 2018					68,302,681
Cumulative translation adjustment																$ (229)
Ending Balances at Jun. 30, 2019					$ 7				977,787	(511)	(981,268)			(3,985)
Ending Balances, shares at Jun. 30, 2019					69,627,148
Beginning Balances at Mar. 31, 2019					$ 7				966,731	(418)	(1,004,835)			(38,515)
Beginning Balances, Shares at Mar. 31, 2019					69,338,697
Issuance of common stock upon exercise of stock options									674					674
Issuance of common stock upon exercise of stock options, Shares					108,374
Issuance of common stock under the employee stock purchase plan ("ESPP")									1,878					1,878
Issuance of common stock under the employee stock purchase plan ("ESPP"), Shares					180,077
Stock-based compensation expense									8,504					8,504
Cumulative translation adjustment										(93)				(93)		(93)
Net income (loss)											23,567			23,567
Ending Balances at Jun. 30, 2019					$ 7				977,787	(511)	(981,268)			$ (3,985)
Ending Balances, shares at Jun. 30, 2019					69,627,148
Beginning Balances at Dec. 31, 2019					$ 7				1,000,763	(558)	(894,998)					105,214	[1]
Beginning Balances, Shares at Dec. 31, 2019					70,366,661
Issuance of common stock upon exercise of stock options									4,438							4,438
Issuance of common stock upon exercise of stock options, Shares					421,850
Issuance of common stock						$ 2,378									$ 2,378
Issuance of common stock, Shares	10,000	134,099
Taxes paid related to net share settlement of bonus payout in RSUs									(880)							(880)
Taxes paid related to net share settlement of bonus payout in RSUs, Shares					(49,616)
Stock-based compensation expense									9,945							9,945
Cumulative translation adjustment										608						608
Net income (loss)											35,572					35,572
Ending Balances at Mar. 31, 2020					$ 7				1,016,644	50	(859,426)					157,275
Ending Balances, shares at Mar. 31, 2020					70,882,994
Beginning Balances at Dec. 31, 2019					$ 7				1,000,763	(558)	(894,998)					105,214	[1]
Beginning Balances, Shares at Dec. 31, 2019					70,366,661
Cumulative translation adjustment																289
Ending Balances at Jun. 30, 2020					$ 7				1,014,022	(257)	(800,395)					213,377
Ending Balances, shares at Jun. 30, 2020					71,353,205
Beginning Balances at Mar. 31, 2020					$ 7				1,016,644	50	(859,426)					157,275
Beginning Balances, Shares at Mar. 31, 2020					70,882,994
Issuance of common stock upon exercise of stock options									3,305							3,305
Issuance of common stock upon exercise of stock options, Shares					289,241
Issuance of common stock under the employee stock purchase plan ("ESPP")									2,557							2,557
Issuance of common stock under the employee stock purchase plan ("ESPP"), Shares					180,970
Purchase of capped call options related to convertible notes due 2026									(18,170)							(18,170)
Unrealized gain in marketable securities										12						12
Stock-based compensation expense									9,686							9,686
Cumulative translation adjustment										(319)						(319)
Net income (loss)											59,031					59,031
Ending Balances at Jun. 30, 2020					$ 7				$ 1,014,022	$ (257)	$ (800,395)					$ 213,377
Ending Balances, shares at Jun. 30, 2020					71,353,205

[1] The consolidated balance sheet as of December 31, 2019 has been derived from the audited consolidated balance sheet included in the Company’s 2019 Annual Report on Form 10-K filed with the Securities and Exchange Commission on February 27, 2020.