EARNINGS PER SHARE (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Earnings Per Share, Basic and Diluted [Abstract]
Income from continuing operations	$ 133	$ 152	$ 237	$ 268
Income from discontinued operations, net of taxes	0	13	0	33
Net income attributable to Quest Diagnostics	133	165	237	301
Less: Earnings allocated to participating securities			1	1
Earnings available to Quest Diagnostics' common stockholders - basic and diluted	$ 133	$ 152	$ 236	$ 267
Weighted average common shares outstanding - basic	144	153	144	155
Stock options and performance share units	1	1	1	2
Weighted average common shares outstanding - diluted	145	154	145	157
Income from continuing operations, per basic share	$ 0.92	$ 0.99	$ 1.64	$ 1.72
Income from discontinued operations, per basic share	$ 0.00	$ 0.08	$ 0.00	$ 0.21
Net income	$ 0.92	$ 1.07	$ 1.64	$ 1.93
Income from continuing operations, per diluted share	$ 0.92	$ 0.99	$ 1.63	$ 1.71
Income from discontinued operations, per diluted share	$ 0.00	$ 0.08	$ 0.00	$ 0.21
Net income	$ 0.92	$ 1.07	$ 1.63	$ 1.92
Stock options and performance share units not included due to their antidilutive effect	3	1	4	2