Sales and Operating Loss Attributable to Business Segments (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011
Total Sales:
Revenues	$ 378	$ 370	$ 1,224	$ 829	$ 289	$ 482	$ 3,021	$ 2,871	$ 2,801	$ 6,663
Operating loss:
Loss from operations									(4,722)	(4,392)
ASSETS
Total assets	2,685				2,308				2,685	2,308
Medical equipment
Total Sales:
Revenues									2,789	6,663
Operating loss:
Loss from operations									3,690	3,775
ASSETS
Total assets	1,739				2,283				1,739	2,283
Radiopharmaceuticals
Total Sales:
Revenues									12	0
Operating loss:
Loss from operations									1,026	396
ASSETS
Total assets	945				24				945	24
Unallocated
Operating loss:
Loss from operations									6	221
ASSETS
Total assets	$ 1				$ 1				$ 1	$ 1