Contingencies (Nu Mark Patent Litigation) (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	Jan. 31, 2017	Dec. 31, 2016	Mar. 31, 2016
Loss Contingencies [Line Items]
Litigation settlement, amount			$ 1,200
Nu Mark Patent Litigation [Member]
Loss Contingencies [Line Items]
Proceeds from legal settlements	$ 21
Litigation settlement, amount		$ 21