UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT) - USD ($) $ in Thousands	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Deficit [Member]	Total
Beginning balance at Dec. 31, 2017		$ 19	$ 198,337	$ (180,841)	$ 17,515
Beginning balance, (in shares) at Dec. 31, 2017		188,764,851
Cumulative effect of a change in accounting principles				440	440
Stock-based compensation expense			674		674
Issuance of Series A preferred stock in connection with private placement, net of issuance costs	$ 20,564
Issuance of Series A preferred stock in connection with private placement, net of issuance costs (in shares)	1,000,000
Issuance of warrants in connection with private placement			4,108		4,108
Beneficial conversion feature of Series A and Series A-1 preferred stock	$ (5,236)		5,236		5,236
Accretion of beneficial conversion feature of Series A and Series A-1 preferred stock	5,236		(5,236)		(5,236)
Accrued dividends on Series A preferred stock	125		(125)		(125)
Issuance of common stock upon vesting of restricted stock units (in shares)		17,190
Net loss				(10,050)	(10,050)
Ending balance at Mar. 31, 2018	$ 20,689	$ 19	202,994	(190,451)	12,562
Ending balance, (in shares) at Mar. 31, 2018	1,000,000	188,782,041
Beginning balance at Dec. 31, 2017		$ 19	198,337	(180,841)	17,515
Beginning balance, (in shares) at Dec. 31, 2017		188,764,851
Net loss					(19,959)
Ending balance at Jun. 30, 2018	$ 21,442	$ 19	202,943	(200,360)	2,602
Ending balance, (in shares) at Jun. 30, 2018	1,010,400	188,887,817
Beginning balance at Mar. 31, 2018	$ 20,689	$ 19	202,994	(190,451)	12,562
Beginning balance, (in shares) at Mar. 31, 2018	1,000,000	188,782,041
Stock-based compensation expense			631		631
Accrued dividends on Series A preferred stock	$ 618		(618)		(618)
Issuance of Series A-1 preferred stock as dividends on Series A preferred stock	$ 135		(135)		(135)
Issuance of Series A-1 preferred stock as dividends on Series A preferred stock (in shares)	10,400
Issuance of common stock upon vesting of restricted stock units (in shares)		12,929
Issuance of common stock upon exercise of stock options			65		65
Issuance of common stock upon exercise of stock options (in shares)		87,507
Issuance of stock, net of issuance costs			6		6
Issuance of stock, net of issuance costs (in shares)		5,340
Net loss				(9,909)	(9,909)
Ending balance at Jun. 30, 2018	$ 21,442	$ 19	202,943	(200,360)	2,602
Ending balance, (in shares) at Jun. 30, 2018	1,010,400	188,887,817
Ending balance at Dec. 31, 2018	$ 22,952	$ 19	206,165	(215,390)	$ (9,206)
Ending balance, (in shares) at Dec. 31, 2018	1,070,400	191,731,152			191,731,152
Stock-based compensation expense			963		$ 963
Issuance of warrants in connection with private placement			440		440
Accrued dividends on Series A preferred stock	$ 625		(625)		(625)
Issuance of Series A-1 preferred stock as dividends on Series A preferred stock	$ 122		(122)		(122)
Issuance of Series A-1 preferred stock as dividends on Series A preferred stock (in shares)	30,000
Issuance costs in connection with at-the-market offering			(71)		(71)
Issuance of common stock upon vesting of restricted stock units (in shares)		83,735
Issuance of common stock upon exercise of stock options		$ 1	160		161
Issuance of common stock upon exercise of stock options (in shares)		413,292
Issuance of stock, net of issuance costs		$ 1	19,530		19,531
Issuance of stock, net of issuance costs (in shares)		14,384,840
Issuance of common stock to non-employee directors			15		15
Issuance of common stock to non-employee directors (in shares)		16,629
Net loss				(9,677)	(9,677)
Ending balance at Mar. 31, 2019	$ 23,699	$ 21	226,455	(225,067)	1,409
Ending balance, (in shares) at Mar. 31, 2019	1,100,400	206,629,648
Beginning balance at Dec. 31, 2018	$ 22,952	$ 19	206,165	(215,390)	$ (9,206)
Beginning balance, (in shares) at Dec. 31, 2018	1,070,400	191,731,152			191,731,152
Net loss					$ (20,338)
Ending balance at Jun. 30, 2019	$ 24,450	$ 21	229,095	(235,728)	$ (6,612)
Ending balance, (in shares) at Jun. 30, 2019	1,130,400	208,012,466			208,012,466
Beginning balance at Mar. 31, 2019	$ 23,699	$ 21	226,455	(225,067)	$ 1,409
Beginning balance, (in shares) at Mar. 31, 2019	1,100,400	206,629,648
Stock-based compensation expense			1,329		1,329
Beneficial conversion feature of Series A and Series A-1 preferred stock	$ (510)		510		510
Accretion of beneficial conversion feature of Series A and Series A-1 preferred stock	510		(510)		(510)
Accrued dividends on Series A preferred stock	626		(626)		(626)
Issuance of Series A-1 preferred stock as dividends on Series A preferred stock	$ 125		(125)		(125)
Issuance of Series A-1 preferred stock as dividends on Series A preferred stock (in shares)	30,000
Issuance of common stock upon vesting of restricted stock units (in shares)		80,001
Issuance of common stock upon exercise of stock options			459		459
Issuance of common stock upon exercise of stock options (in shares)		753,775
Issuance of stock, net of issuance costs			1,589		1,589
Issuance of stock, net of issuance costs (in shares)		541,025
Issuance of common stock to non-employee directors			14		14
Issuance of common stock to non-employee directors (in shares)		8,017
Net loss					(10,661)
Ending balance at Jun. 30, 2019	$ 24,450	$ 21	$ 229,095	$ (235,728)	$ (6,612)
Ending balance, (in shares) at Jun. 30, 2019	1,130,400	208,012,466			208,012,466

Corindus Vascular Robotics, Inc. 10-Q