Operating Segments and Concentrations of Credit Risk (Major Customers) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Allocated Share-based Compensation Expense	$ 96,538	$ 67,148	$ 56,432
Concentration Risk, Percentage	88.00%	89.00%	90.00%
AT&T [Member]
Concentration Risk, Percentage	27.00%	27.00%	26.00%
Sprint [Member]
Concentration Risk, Percentage	16.00%	19.00%	25.00%
Verizon Wireless [Member]
Concentration Risk, Percentage	22.00%	21.00%	18.00%
T-Mobile [Member]
Concentration Risk, Percentage	23.00%	22.00%	21.00%
Selling, General and Administrative Expenses [Member]
Allocated Share-based Compensation Expense	$ 74,500	$ 52,800	$ 44,900
Cost of Sales [Member]
Allocated Share-based Compensation Expense	$ 22,100	$ 14,300	$ 11,500