Business Description and Summary of Significant Accounting Policies (Details Narrative)							3 Months Ended	12 Months Ended
	May 18, 2018 USD ($) $ / shares shares	Apr. 27, 2018 $ / shares shares	Feb. 14, 2018 USD ($) $ / shares shares	Feb. 14, 2018 USD ($) $ / shares shares	Feb. 13, 2018 shares	Jan. 17, 2018 USD ($) $ / shares shares	Mar. 31, 2018	Dec. 31, 2018 USD ($) shares	Dec. 31, 2017 USD ($) shares	Jan. 02, 2018 USD ($)	Dec. 31, 2016 USD ($)
Reverse stock split, description				Upon the effectiveness of the Reverse Stock Split, every 12 shares of our issued and outstanding common stock automatically converted into one share of common stock, without any change in the par value per share.	1-for-12 reverse split
Cash on hand | $								$ 6,797,000	$ 2,856,000		$ 2,578,000
Accumulated deficit | $								(215,045,000)	(144,946,000)
Debt conversion, converted instrument, amount | $								$ 71,865,000
Stock issued during period, shares, new issues	129							129
Shares issued, price per share | $ / shares	$ 0.0869816
Stock issued during period, value, new issues | $	$ 900,000							$ 900
Common stock, shares authorized								50,000,000	50,000,000
Preferred stock, shares authorized								10,000,000	10,000,000
Description of royalty opportunities				(i) issue new securities; (ii) incur over $0.25 million of debt in a fiscal year; (iii) sell or transfer over $0.25 million of our assets or businesses or our subsidiaries in a fiscal year; (iv)acquire over $0.25 million of assets or properties in a fiscal year; (v)make capital expenditures over $0.125 million individually, or $1.5 million in the aggregate during a fiscal year; (vi) approve our annual budget; (vii) hire or terminate our chief executive officer; (viii)appoint or remove the chairperson of the Board; and (ix) make, loans to, investments in, or purchase, or permit any subsidiary to purchase, any stock or other securities in another entity in excess of $0.25 million in a fiscal year.
Ownership interest percentage description								(a) upon the mutual written agreement of all the parties, (b) upon written notice of the Company or an Investor, if such Investor's ownership percentage of our then outstanding common stock is less than 10%, or (c) upon written notice by the Investors. PWPI and PWIMF's right to purchase from us a pro rata amount of any new securities will also terminate at such time as their aggregate ownership percentage of our then outstanding common stock is less than 8.5%.
Impairment of long-lived assets | $
Adjustment to decrease opening balance of retained earnings | $										$ 24,000
Antidilutive securities excluded from computation of earnings per share, amount								2,207,567	587,382
Operating lease liability and right-of-use asset | $								$ 3,000,000
Securities Purchase Agreement [Member]
Stock issued during period, shares, new issues				945,819
Shares issued, price per share | $ / shares			$ 7.20	$ 7.20
Stock issued during period, value, new issues | $				$ 6,800,000
Reverse Stock Split Before [Member]
Common stock, shares authorized					95,000,000
Preferred stock, shares authorized					50,000,000
Reverse Stock Split After [Member]
Common stock, shares authorized					50,000,000
Preferred stock, shares authorized					10,000,000
Maximum [Member]
Stock issued during period, shares, new issues	1,137,515
Minimum [Member]
Outstanding common stock in percentage			40.00%	40.00%
2017 Notes [Member]
Debt conversion, converted instrument, shares issued						189,645
6.00% Convertible Senior Unsecured Notes [Member]
Debt instrument due date description			Convertible senior unsecured notes due 2021			Convertible senior unsecured notes due 2021	Convertible senior unsecured notes due 2021
Debt instrument, conversion price per share | $ / shares			$ 7.20	$ 7.20
Debt conversion, converted instrument, shares issued			10,401,309	10,401,309		189,645
Debt conversion, converted instrument, amount | $			$ 70,300,000			$ 1,600,000
Debt instrument, convertible, conversion ratio			138.8889
Debt instrument, face amount | $			$ 1,000,000	$ 1,000,000
6.00% Convertible Senior Unsecured Notes [Member] | OrbiMed Royalty Opportunities II, LP [Member]
Non-controlling interest, ownership percentage by parent			70.00%	70.00%
6.00% Convertible Senior Unsecured Notes [Member] | 2017 Notes [Member]
Debt instrument due date description						Convertible senior unsecured notes due 2021
Debt instrument, conversion price per share | $ / shares						$ 9.11
Restructuring Agreement [Member]
Shares issued, price per share | $ / shares		$ 7.20
Rights offering expired		Jun. 18, 2018
Restructuring Agreement [Member] | Maximum [Member]
Stock issued during period, shares, new issues		1,137,515
Orbi Med [Member] | Amended and Restated Credit Agreement [Member]
Debt capital | $								10,000,000
Cash and accounts receivable | $								$ 16,700,000
Management evaluation description								Management's evaluation of going concern was conducted as part of the multiple discussions with the Xtant Board of Directors' review of the Annual Operating Plan. The Company and OrbiMed have entered into an Amended and Restated Credit Agreement and commitment for up to an additional $10 million in debt capital. Management believes these actions along with the $16.7 million of cash and accounts receivable on the balance sheet as of December 31, 2018 will enable the Company to continue as a going concern through the end of March 2020.