Stock-Based Compensation Plans (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 17,446	$ 14,921	$ 18,227
Tax benefit	(5,776)	(5,759)	(6,061)
Stock-based compensation expense, net of tax	11,670	9,162	12,166
Cost of equipment sales
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	1,004	886	1,212
Cost of software
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	95	0	0
Cost of support services
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	607	382	522
Cost of business services
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	694	527	721
Selling, general and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	14,028	11,099	15,176
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	1,018	435	596
Discontinued operations | Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 0	$ 1,592	$ 0