Equity, Common Stock by Transaction (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Common Shares [Abstract]
Common shares, authorized (in shares)	75,000,000	75,000,000
Common shares, par value (in dollars per share)	$ 0	$ 0
Common shares, issued (in shares)	51,183,318	50,321,962
Common shares, outstanding (in shares)	49,383,209	49,035,788
Treasury stock (in shares)	1,800,109	1,286,174
Proceeds from exercises of stock options	$ 286,552	$ 223,914	$ 605,998
Proceeds from exercises of warrants	0	425,000	22,861,458
Exercise of options (in shares)			125,000	125,000
Cash received from investors	250,000
Shares received by subsidiary (in shares)	592,533
Shares value received by subsidiary		0
Sale of stock by subsidiary (in shares)	78,598
Proceeds from sale of stock by subsidiary	282,826
Sales of common shares (in shares)	314,386
Proceeds from sale of equity	1,131,279
Aggregate offering price	25,000,000
Fees recognized in connection with sale of shares	37,279
Loss adjustment from sale of common shares held by LifeMap	91,780
Common shares retired as payment for exercise of options (in shares)		6,435
Treasury shares issued as part of investment in subsidiary (in shares)	592,533
Stock Options [Member]
Common Shares [Abstract]
Proceeds from exercises of stock options	286,552	223,914
Options exercises in period, weighted average exercise price (in dollars per share)	$ 2.91	$ 0.50
Exercise of options (in shares)	98,541	450,660
Warrant [Member]
Common Shares [Abstract]
Proceeds from exercises of warrants		425,000
OncoCyte Corporation [Member]
Common Shares [Abstract]
Shares received by subsidiary (in shares)		1,286,174
Treasury shares issued as part of investment in subsidiary (in shares)		1,286,174
Bio Time ownership (in hundredths)	75.30%	75.30%
CTI [Member]
Common Shares [Abstract]
Common shares issued as part of acquisition of CTI assets (in shares)		261,959
XenneX, Inc. [Member]
Common Shares [Abstract]
Common shares issued as part of merger (in shares)	448,429
Glycosan [Member]
Common Shares [Abstract]
Common shares issued as part of merger (in shares)		332,903
Warrants issued (in shares)		206,613
LifeMap Sciences, Inc. [Member]
Common Shares [Abstract]
Treasury stock (in shares)	513,935
Cash received from investors	250,000
Shares received by subsidiary (in shares)	592,533
Shares value received by subsidiary	$ 2,750,003
Number of common shares received in exchange for capital contribution (in shares)	1,714,287
Treasury shares issued as part of investment in subsidiary (in shares)	592,533
Bio Time ownership (in hundredths)	73.20%