EARNINGS PER SHARE (Details) (USD $) In Thousands, except Share data	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Earnings Per Share
Income from continuing operations	$ 163,650	$ 194,881	$ 110,163	$ 357,381
Loss from discontinued operations, net of taxes	(507)	(266)	(881)	(318)
Net income attributable to Quest Diagnostics	163,143	194,615	109,282	357,063
Less: Earnings allocated to participating securities	877	928	967	1,588
Earnings (loss) available to Quest Diagnostics' common stockholders - basic and diluted	$ 162,773	$ 193,953	$ 109,196	$ 355,793
Weighted average common shares outstanding - basic	157,607,000	178,920,000	159,548,000	179,570,000
Stock options and performance share units	1,745,000	1,840,000	1,730,000	2,002,000
Weighted average common shares outstanding - diluted	159,352,000	180,760,000	161,278,000	181,572,000
Income from continuing operations	$ 1.03	$ 1.08	$ 0.68	$ 1.98
Loss from discontinued operations, per basic share
Net income - per basic share	$ 1.03	$ 1.08	$ 0.68	$ 1.98
Income from continuing operations	$ 1.02	$ 1.07	$ 0.68	$ 1.96
Net income - per diluted share	$ 1.02	$ 1.07	$ 0.67	$ 1.96
Loss from discontinued operations, per diluted share			$ (0.01)
Stock options and performance share unit not included due to their antidilutive effect	2,300,000	3,100,000	2,200,000	2,900,000