SUMMARIZED FINANCIAL INFORMATION (Condensed Consolidating Statement of Operations) (Details) (USD $) In Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Net revenues	$ 1,906,405	$ 1,864,655	$ 5,631,183	$ 5,544,885
Cost of services	1,116,574	1,091,465	3,317,966	3,236,809
Selling, general and administrative	446,595	426,562	1,357,242	1,276,707
Amortization of intangible assets	19,402	9,915	47,843	28,544
Royalty (income) expense
Other operating (income) expense, net	1,781	(154)	238,265	1,502
Total operating costs and expenses	1,584,352	1,527,788	4,961,316	4,543,562
Operating income	322,053	336,867	669,867	1,001,323
Non-operating (expense) income, net	(38,784)	(25,849)	(105,864)	(83,929)
Income from continuing operations before taxes	283,269	311,018	564,003	917,394
Income tax expense	101,126	102,902	256,114	333,931
Income from continuing operations	182,143	208,116	307,889	583,463
Loss from discontinued operations, net of taxes	(250)	(360)	(1,131)	(678)
Equity earnings from subsidiaries
Net income	181,893	207,756	306,758	582,785
Less: Net income attributable to noncontrolling interests	10,045	9,681	25,628	27,647
Net income attributable to Quest Diagnostics	171,848	198,075	281,130	555,138
Parent [Member]
Net revenues	195,552	209,156	597,362	638,796
Cost of services	130,350	133,527	375,283	385,350
Selling, general and administrative	29,507	32,043	103,469	76,394
Amortization of intangible assets	392	618	1,098	653
Royalty (income) expense	(104,113)	(105,055)	(310,887)	(311,863)
Other operating (income) expense, net	(382)	1,499	235,924	1,178
Total operating costs and expenses	55,754	62,632	404,887	151,712
Operating income	139,798	146,524	192,475	487,084
Non-operating (expense) income, net	(43,595)	(33,314)	(127,721)	(103,847)
Income from continuing operations before taxes	96,203	113,210	64,754	383,237
Income tax expense	32,178	29,294	68,946	133,356
Income from continuing operations	64,025	83,916	(4,192)	249,881
Loss from discontinued operations, net of taxes
Equity earnings from subsidiaries	107,823	114,159	285,322	305,257
Net income	171,848	198,075	281,130	555,138
Less: Net income attributable to noncontrolling interests
Net income attributable to Quest Diagnostics	171,848	198,075	281,130	555,138
Subsidiary Guarantors [Member]
Net revenues	1,591,099	1,540,714	4,671,748	4,564,026
Cost of services	920,778	894,001	2,737,849	2,660,571
Selling, general and administrative	332,204	307,533	986,510	934,116
Amortization of intangible assets	17,654	7,597	41,851	22,829
Royalty (income) expense	104,113	105,055	310,887	311,863
Other operating (income) expense, net	455	73	826	539
Total operating costs and expenses	1,375,204	1,314,259	4,077,923	3,929,918
Operating income	215,895	226,455	593,825	634,108
Non-operating (expense) income, net	(53,859)	(58,341)	(164,314)	(179,726)
Income from continuing operations before taxes	162,036	168,114	429,511	454,382
Income tax expense	63,823	66,251	169,566	179,329
Income from continuing operations	98,213	101,863	259,945	275,053
Loss from discontinued operations, net of taxes	(250)	(360)	(1,131)	(678)
Equity earnings from subsidiaries
Net income	97,963	101,503	258,814	274,375
Less: Net income attributable to noncontrolling interests
Net income attributable to Quest Diagnostics	97,963	101,503	258,814	274,375
Non-Guarantor Subsidiaries [Member]
Net revenues	185,257	186,307	566,136	560,016
Cost of services	65,446	63,937	204,834	190,888
Selling, general and administrative	92,314	94,515	289,517	288,619
Amortization of intangible assets	1,356	1,700	4,894	5,062
Royalty (income) expense
Other operating (income) expense, net	1,708	(1,726)	1,515	(215)
Total operating costs and expenses	160,824	158,426	500,760	484,354
Operating income	24,433	27,881	65,376	75,662
Non-operating (expense) income, net	597	1,813	4,362	4,113
Income from continuing operations before taxes	25,030	29,694	69,738	79,775
Income tax expense	5,125	7,357	17,602	21,246
Income from continuing operations	19,905	22,337	52,136	58,529
Loss from discontinued operations, net of taxes
Equity earnings from subsidiaries
Net income	19,905	22,337	52,136	58,529
Less: Net income attributable to noncontrolling interests	10,045	9,681	25,628	27,647
Net income attributable to Quest Diagnostics	9,860	12,656	26,508	30,882
Eliminations [Member]
Net revenues	(65,503)	(71,522)	(204,063)	(217,953)
Cost of services
Selling, general and administrative	(7,430)	(7,529)	(22,254)	(22,422)
Amortization of intangible assets
Royalty (income) expense
Other operating (income) expense, net
Total operating costs and expenses	(7,430)	(7,529)	(22,254)	(22,422)
Operating income	(58,073)	(63,993)	(181,809)	(195,531)
Non-operating (expense) income, net	58,073	63,993	181,809	195,531
Income from continuing operations before taxes
Income tax expense
Income from continuing operations
Loss from discontinued operations, net of taxes
Equity earnings from subsidiaries	(107,823)	(114,159)	(285,322)	(305,257)
Net income	(107,823)	(114,159)	(285,322)	(305,257)
Less: Net income attributable to noncontrolling interests
Net income attributable to Quest Diagnostics	$ (107,823)	$ (114,159)	$ (285,322)	$ (305,257)