Collaborative arrangements (Textuals 1) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Product sales	$ 4,799	$ 4,647	$ 4,595	$ 4,151	$ 4,337	$ 4,201	$ 4,200	$ 3,901	$ 18,192	$ 16,639	$ 15,295
Glaxo Group Limited [Member] | Selling, General and Administrative [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Cost recoveries									(16)	10	30
Glaxo Group Limited [Member] | Primary Territories [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Product sales									$ 219	$ 139	$ 62