Segmental Reporting (Revenues and Accounts Receivable by Major Customers) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenue, Major Customer [Line Items]
Product sales	$ 5,830.4	$ 4,757.5	$ 4,252.9
Customer concentration risk
Revenue, Major Customer [Line Items]
Revenue by major customer, percent	47.00%
Cardinal Health Inc.
Revenue, Major Customer [Line Items]
Product sales	979.9	853.7	1,035.7
Accounts receivable by major customer	164.5	149.5
Cardinal Health Inc. | Product Revenue
Revenue, Major Customer [Line Items]
Revenue by major customer, percent	17.00%	18.00%	24.00%
McKesson Corp.
Revenue, Major Customer [Line Items]
Product sales	1,021.0	902.9	835.9
Accounts receivable by major customer	179.4	161.3
McKesson Corp. | Product Revenue
Revenue, Major Customer [Line Items]
Revenue by major customer, percent	18.00%	19.00%	20.00%
AmerisourceBergen Corp
Revenue, Major Customer [Line Items]
Product sales	759.2	721.0	307.4
Accounts receivable by major customer	$ 134.9	$ 164.6
AmerisourceBergen Corp | Product Revenue
Revenue, Major Customer [Line Items]
Revenue by major customer, percent	13.00%	15.00%	7.00%