Restructuring (Restructuring Charges by Segment) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Restructuring Cost and Reserve [Line Items]
Restructuring	$ 46,065	$ 33,951
2014 Restructuring Program [Member] | Enterprise and Service Provider Division [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring	0	834
2014 Restructuring Program [Member] | Mobility Apps [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring	0	50
2015 Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring	6,974
2015 Restructuring Program [Member] | Enterprise and Service Provider Division [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring	7,053	32,755
2015 Restructuring Program [Member] | Mobility Apps [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring	(79)	312
2015 Other Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring	39,091
2015 Other Restructuring Program [Member] | Enterprise and Service Provider Division [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring	38,503	0
2015 Other Restructuring Program [Member] | Mobility Apps [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring	$ 588	$ 0