Shareholders' Equity (Details) - USD ($) $ / shares in Units, $ in Millions	Jul. 05, 2016	Jun. 21, 2016	Jun. 16, 2016	May 13, 2016	Jun. 30, 2016	Dec. 31, 2015
Preferred Shares [Abstract]
Preferred shares, shares authorized (in shares)					2,000,000	2,000,000
Common Shares [Abstract]
Common stock, authorized (in shares)					150,000,000	150,000,000
Common stock, par value (in dollars per share)					$ 0	$ 0
Common shares, shares issued (in shares)					102,288,000	94,894,000
Common shares, shares outstanding (in shares)					101,668,000	90,421,000
Treasury stock (in shares)					620,000	4,473,000
Common shares, new shares issued (in shares)		7,322,176
Proceeds from sale of stock		$ 16.4
Over-Allotment Option [Member] | Subsequent Event [Member]
Common Shares [Abstract]
Common shares, new shares issued (in shares)	1,098,326
Proceeds from sale of stock	$ 2.5
Asterias Biotherapeutics [Member]
Common Shares [Abstract]
Common shares, shares outstanding (in shares)				3,852,880	21,700,000
Proceeds from sale of stock				$ 16.2
Oppenheimer & Co. Inc [Member]
Common Shares [Abstract]
Common stock, par value (in dollars per share)			$ 0
Common shares, shares issued (in shares)			7,322,176
Disposal of common stock period			90 days
Purchase price per share (in dollars per share)			$ 2.39