Employee Termination Program - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Restructuring Cost And Reserve [Line Items]
Selling, general and administrative	$ 207,370	$ 198,821
Net income attributable to SNI	199,900	290,897
Reorganization [Member]
Restructuring Cost And Reserve [Line Items]
Costs for severance, retention, relocation and benefit cost	$ 100	7,300
Selling, general and administrative		5,600
Cost of services		1,700
Net income attributable to SNI		$ (4,500)