CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Income Statement [Abstract]
Net revenues	$ 1,786,647	$ 1,908,697
Operating costs and expenses:
Cost of services	1,091,834	1,109,164
Selling, general and administrative	447,869	483,252
Amortization of intangible assets	19,284	18,825
Other operating expense (income), net	666	(363)
Total operating costs and expenses	1,559,653	1,610,878
Operating income	226,994	297,819
Other income (expense):
Interest expense, net	(39,865)	(42,102)
Equity earnings in unconsolidated joint ventures	6,146	7,609
Other income, net	3,391	4,756
Total non-operating expenses, net	(30,328)	(29,737)
Income from continuing operations before taxes	196,666	268,082
Income tax expense	73,337	102,562
Income from continuing operations	123,329	165,520
Income from discontinued operations, net of taxes	20,288	2,995
Net income	143,617	168,515
Less: Net income attributable to noncontrolling interests	7,838	9,397
Net income attributable to Quest Diagnostics	135,779	159,118
Amounts attributable to Quest Diagnostics' stockholders:
Income from continuing operations	115,491	156,123
Income from discontinued operations, net of taxes	20,288	2,995
Net income attributable to Quest Diagnostics	$ 135,779	$ 159,118
Earnings per share attributable to Quest Diagnostics' common stockholders - basic:
Income from continuing operations	$ 0.73	$ 0.98
Income from discontinued operations, per basic share	$ 0.13	$ 0.02
Net income	$ 0.86	$ 1.00
Earnings per share attributable to Quest Diagnostics' common stockholders - diluted:
Income from continuing operations	$ 0.72	$ 0.97
Income from discontinued operations, per diluted share	$ 0.13	$ 0.02
Net income	$ 0.85	$ 0.99
Weighted average common shares outstanding:
Basic	158,098	158,293
Diluted	159,406	159,706
Dividends per common share	$ 0.30	$ 0.17