CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Income Statement [Abstract]
Net revenues	$ 1,851,439	$ 1,906,405	$ 5,694,705	$ 5,631,183
Operating costs and expenses:
Cost of services	1,089,718	1,116,574	3,316,770	3,317,966
Selling, general and administrative	432,627	446,595	1,374,056	1,357,242
Amortization of intangible assets	19,961	19,402	60,361	47,843
Other operating expense, net	400	1,781	452	238,265
Total operating costs and expenses	1,542,706	1,584,352	4,751,639	4,961,316
Operating income	308,733	322,053	943,066	669,867
Other income (expense):
Interest expense, net	(41,028)	(43,408)	(125,303)	(127,918)
Equity earnings in unconsolidated joint ventures	4,662	7,301	19,643	22,869
Other income (expense), net	2,472	(2,677)	5,973	(815)
Total non-operating expenses, net	(33,894)	(38,784)	(99,687)	(105,864)
Income from continuing operations before taxes	274,839	283,269	843,379	564,003
Income tax expense	103,340	101,126	317,111	256,114
Income from continuing operations	171,499	182,143	526,268	307,889
Income (loss) from discontinued operations, net of taxes	39	(250)	258	(1,131)
Net income	171,538	181,893	526,526	306,758
Less: Net income attributable to noncontrolling interests	8,456	10,045	26,621	25,628
Net income attributable to Quest Diagnostics	163,082	171,848	499,905	281,130
Amounts attributable to Quest Diagnostics' stockholders:
Income from continuing operations	163,043	172,098	499,647	282,261
Income (loss) from discontinued operations, net of taxes	39	(250)	258	(1,131)
Net income attributable to Quest Diagnostics	$ 163,082	$ 171,848	$ 499,905	$ 281,130
Earnings per share attributable to Quest Diagnostics' common stockholders - basic:
Income from continuing operations	$ 1.02	$ 1.08	$ 3.14	$ 1.76
Income (loss) from discontinued operations, per basic share	$ 0.00	$ 0.00	$ 0.00	$ (0.01)
Net income	$ 1.02	$ 1.08	$ 3.14	$ 1.75
Earnings per share attributable to Quest Diagnostics' common stockholders - diluted:
Income from continuing operations	$ 1.01	$ 1.08	$ 3.11	$ 1.75
Income (loss) from discontinued operations, per diluted share	$ 0.00	$ (0.01)	$ 0.00	$ (0.01)
Net income	$ 1.01	$ 1.07	$ 3.11	$ 1.74
Weighted average common shares outstanding:
Basic	158,783	157,816	158,518	158,971
Diluted	160,702	159,002	160,064	160,519
Dividends per common share	$ 0.17	$ 0.10	$ 0.51	$ 0.30