Acquisitions (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Significant Acquisitions and Disposals [Line Items]
Other Cost and Expense, Operating	$ 5,154	$ 6,718	$ 2,332	$ 1,889	$ 65,297	$ 72,782	$ 5,285	$ 5,765	$ 16,093	$ 149,129	$ 28,349
Payments to Acquire Businesses, Net of Cash Acquired									101,933	111,812	92,889
Initial tender offer for Pharmerica									$ 15.00
Acquisition And Other Related Costs [Member]
Significant Acquisitions and Disposals [Line Items]
Other Cost and Expense, Operating									$ 25,549	$ 5,319	$ 1,399