Schedule of Shareholders' Equity (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
BALANCE AT APRIL 1, 2019	$ 104,758	$ 111,247	$ 161,236	$ 92,246	$ 111,247	$ 92,246
Shares issued upon vesting of restricted stock units, net of shares retired to pay employees’ taxes	(11)	(2)	(2)	(75)
Stock-based compensation	606	626	762	1,361
Foreign currency translation loss	(1,120)	1,315	(487)	(732)	195	(1,219)
Financing related fees	(10)
Shares issued in connection with the Asterias Merger				32,353
Shares retired in connection with the Asterias Merger				(3,435)
Stock-based compensation for shares issued upon vesting of Asterias restricted stock units attributable to post combination services				79
Adjustment upon adoption of leasing standard				143
Shares issued for settlement of BioTime Warrants			302
NET INCOME/(LOSS)	(6,530)	(8,428)	(30,052)	39,296	(14,958)	9,244
BALANCE AT JUNE 30, 2019	97,693	104,758	131,759	161,236	97,693	131,759
Preferred Stock [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
BALANCE AT APRIL 1, 2019
Balance, shares
Shares issued upon vesting of restricted stock units, net of shares retired to pay employees’ taxes
Shares issued upon vesting of restricted stock units, net of shares retired to pay employees taxes, shares
Stock-based compensation
Foreign currency translation loss
Shares issued in connection with the Asterias Merger
Shares issued in connection with the Asterias Merger
Shares retired in connection with the Asterias Merger
Shares retired in connection with the Asterias Merger
Stock-based compensation for shares issued upon vesting of Asterias restricted stock units attributable to post combination services
Stock-based compensation for shares issued upon vesting of Asterias restricted stock units attributable to post combination services
Adjustment upon adoption of leasing standard
Shares issued for settlement of BioTime Warrants
Shares issued for settlement of BioTime Warrants, shares
NET INCOME/(LOSS)
BALANCE AT JUNE 30, 2019
Balance, shares
Common Stock [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
BALANCE AT APRIL 1, 2019	$ 387,686	$ 387,062	$ 384,553	$ 354,270	$ 387,062	$ 354,270
Balance, shares	149,818	149,804	149,388	127,136	149,804	127,136
Shares issued upon vesting of restricted stock units, net of shares retired to pay employees’ taxes	$ (11)	$ (2)	$ (2)	$ (75)
Shares issued upon vesting of restricted stock units, net of shares retired to pay employees taxes, shares	13	14	3	118
Stock-based compensation	$ 606	$ 626	$ 762	$ 1,361
Foreign currency translation loss
Financing related fees	(10)
Shares issued in connection with the Asterias Merger				$ 32,353
Shares issued in connection with the Asterias Merger				24,696
Shares retired in connection with the Asterias Merger				$ (3,435)
Shares retired in connection with the Asterias Merger				(2,622)
Stock-based compensation for shares issued upon vesting of Asterias restricted stock units attributable to post combination services				$ 79
Stock-based compensation for shares issued upon vesting of Asterias restricted stock units attributable to post combination services				60
Adjustment upon adoption of leasing standard
Shares issued for settlement of BioTime Warrants			$ 302
Shares issued for settlement of BioTime Warrants, shares			252
NET INCOME/(LOSS)
BALANCE AT JUNE 30, 2019	$ 388,271	$ 387,686	$ 385,615	$ 384,553	$ 388,271	$ 385,615
Balance, shares	149,831	149,818	149,643	149,388	149,831	149,643
Accumulated Deficit [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
BALANCE AT APRIL 1, 2019	$ (281,821)	$ (273,422)	$ (222,403)	$ (261,856)	$ (273,422)	$ (261,856)
Shares issued upon vesting of restricted stock units, net of shares retired to pay employees’ taxes
Stock-based compensation
Foreign currency translation loss
Shares issued in connection with the Asterias Merger
Shares retired in connection with the Asterias Merger
Stock-based compensation for shares issued upon vesting of Asterias restricted stock units attributable to post combination services
Adjustment upon adoption of leasing standard				143
Shares issued for settlement of BioTime Warrants
NET INCOME/(LOSS)	(6,522)	(8,399)	(30,032)	39,310
BALANCE AT JUNE 30, 2019	(288,343)	(281,821)	(252,435)	(222,403)	(288,343)	(252,435)
Noncontrolling Inteests Deficit [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
BALANCE AT APRIL 1, 2019	(1,741)	(1,712)	(1,608)	(1,594)	(1,712)	(1,594)
Shares issued upon vesting of restricted stock units, net of shares retired to pay employees’ taxes
Stock-based compensation
Foreign currency translation loss
Shares issued in connection with the Asterias Merger
Shares retired in connection with the Asterias Merger
Stock-based compensation for shares issued upon vesting of Asterias restricted stock units attributable to post combination services
Adjustment upon adoption of leasing standard
Shares issued for settlement of BioTime Warrants
NET INCOME/(LOSS)	(8)	(29)	(20)	(14)
BALANCE AT JUNE 30, 2019	(1,749)	(1,741)	(1,628)	(1,608)	(1,749)	(1,628)
AOCI Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
BALANCE AT APRIL 1, 2019	634	(681)	694	1,426	(681)	1,426
Shares issued upon vesting of restricted stock units, net of shares retired to pay employees’ taxes
Stock-based compensation
Foreign currency translation loss	(1,120)	1,315	(487)	(732)
Shares issued in connection with the Asterias Merger
Shares retired in connection with the Asterias Merger
Stock-based compensation for shares issued upon vesting of Asterias restricted stock units attributable to post combination services
Adjustment upon adoption of leasing standard
Shares issued for settlement of BioTime Warrants
NET INCOME/(LOSS)
BALANCE AT JUNE 30, 2019	$ (486)	$ 634	$ 207	$ 694	$ (486)	$ 207