Consolidated Statements of Stockholders' Equity (Deficit) - USD ($)	Class E Redeemable Convertible Units [Member]	Class A Units [Member] Additional Paid-in Capital [Member]	Class A Units [Member]	Class B Units [Member]	Class C Units[Member]	Class D Units [Member]	Convertible Preferred Stock [Member] Preferred Stock [Member]	Convertible Preferred Stock [Member]	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Total
Balance at Dec. 31, 2014	$ 37,052,000										$ 341,343,000	$ (496,763,000)	$ (155,420,000)
Balance, Shares at Dec. 31, 2014	3,438,984		50,882,656	1	1	4,373,674
Issuance to settle obligation	$ 6,606,000	$ 10,541,000	$ 10,541,000
Issuance to settle obligation, shares	574,392		1,808,334
Issuance of units to non-employee directors	$ 63,000
Issuance of units to non-employee directors, shares	10,435
Accretion of units fee discount and repayment premium											(4,302,000)		(4,302,000)
Accretion of units fee discount and repayment premium	$ 4,302,000
Share-based compensation expense											10,324,000		10,324,000
Issuance of units	$ 10,833,000	15,000,000	$ 15,000,000
Issuance of units, shares	945,441		1,250,000
Issuance of units related to option exercises		30,000	$ 30,000										$ 4,800
Issuance of units related to option exercises, shares			5,011										772
Net loss												(147,082,000)	$ (147,082,000)
Balance at Dec. 31, 2015	$ 58,856,000										372,936,000	(643,845,000)	(270,909,000)
Balance, Shares at Dec. 31, 2015	4,969,252		53,946,001	1	1	4,373,674
Issuance to settle obligation	$ 13,460,000	125,000	$ 125,000							$ 1,000	2,499,000		2,500,000
Issuance to settle obligation, shares	1,170,437		25,000							208,334
Equity raised through issuance of Class E units, net	$ 5,500,000
Equity raised through issuance of Class E units, net, shares	478,266
Accretion of units fee discount and repayment premium											(5,812,000)		(5,812,000)
Accretion of units fee discount and repayment premium	$ 5,812,000
Share-based compensation expense											47,217,000		$ 47,217,000
Issuance of units related to option exercises		$ 41,000	$ 41,000
Issuance of units related to option exercises, shares			7,200										1,109
Common stock issued in private placement, net, shares	478,266
Common stock and warrants issued in public offering, net										$ 6,000	69,744,000		$ 69,750,000
Common stock and warrants issued in public offering, net, shares										6,250,000
Initial public offering costs											(3,739,000)		(3,739,000)
Beneficial conversion feature on Class E units at IPO											13,431,000	(13,431,000)	13,431,000
Cummulative effect of change in accounting principle - ASU 2016-09 forfeiture adjustment											1,990,000	(1,990,000)
Corporate conversion from Kadmon Holdings, LLC to Kadmon Holdings, Inc.											(720,618,000)	720,618,000
Corporate conversion to common stock	$ (83,628,000)									$ 19,000	83,607,000		83,626,000
Corporate conversion to common stock, shares	(6,617,955)		(53,978,201)	(1)	(1)	(4,373,674)				19,585,865
Conversion of convertible debt							$ 30,000,000	$ 30,000,000		$ 19,000	182,712,000		182,731,000
Conversion of convertible debt, shares							30,000			19,034,467
Beneficial conversion feature on convertible debt											45,683,000		45,683,000
Beneficial conversion feature on convertible preferred stock									$ 7,660,000			(7,660,000)	7,660,000
Accretion of dividends on convertible preferred stock								600,000	642,000			(642,000)	642,000
Reclassification of warrants to equity											1,716,000		1,716,000
Beneficial conversion feature on warrants											634,000		634,000
Net loss												(208,755,000)	(208,755,000)
Balance at Dec. 31, 2016									$ 38,302,000	$ 45,000	92,166,000	(155,705,000)	(25,192,000)
Balance, Shares at Dec. 31, 2016									30,000	45,078,666
Share-based compensation expense											12,354,000		12,354,000
Common stock issued under ESPP plan											30,000		30,000
Common stock issued for warrant exercises											37,000		37,000
Common stock issued for warrant exercises, shares										11,839
Common stock issued under ESPP plan, shares										10,594
Common stock issued in private placement, net										$ 7,000	19,209,000		19,216,000
Common stock issued in private placement, net, shares										6,767,855
Common stock and warrants issued in public offering, net										$ 27,000	75,060,000		75,087,000
Common stock and warrants issued in public offering, net, shares										26,775,000
Beneficial conversion feature on convertible preferred stock									$ 384,000			(384,000)	384,000
Accretion of dividends on convertible preferred stock								$ 1,500,000	1,534,000			(1,534,000)	1,534,000
Net loss												(79,774,000)	(79,774,000)
Balance at Dec. 31, 2017									$ 40,220,000	$ 79,000	$ 198,856,000	$ (237,397,000)	$ 1,758,000
Balance, Shares at Dec. 31, 2017									30,000	78,643,954