Consolidated Statements of Income (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenue
Product revenue	$ 1,227	$ 1,230	$ 1,297
Service revenue	1,505	1,462	1,368
Total revenue	2,732	2,692	2,665
Costs and operating expenses
Cost of products	443	433	416
Cost of services	810	786	758
Selling, general and administrative expenses	770	757	728
Research and development expenses	206	184	183
Total costs and operating expenses	2,229	2,160	2,085
Income from operations	503	532	580
Other expense, net	(9)	(24)	(2)
Income before income taxes	494	508	578
Income tax expense	127	131	159
Net income	$ 367	$ 377	$ 419
Net income per common share
Basic (in usd per share)	$ 2.36	$ 2.31	$ 2.49
Diluted (in usd per share)	$ 2.33	$ 2.27	$ 2.44
Weighted average common shares outstanding
Basic (in shares)	155.3	163.4	168.2
Diluted (in shares)	157.8	166.4	171.7