Fair Value of Financial Instruments (Other Investments - Pensare) (Narrative) (Details) $ / shares in Units, warrant in Millions		3 Months Ended		9 Months Ended
	Sep. 30, 2018 warrant $ / shares	Sep. 30, 2018 USD ($) warrant	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($) warrant
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity investments, upward price adjustment, amount				$ 0
Equity investments, downward price adjustment, amount				$ 0
Pensare [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity investment and warrants, amount paid (in dollars)			$ 2,000,000
Equity investment, ownership percentage	4.00%	4.00%		4.00%
Derivative instruments, number held | warrant	2.0	2.0		2.0
Equity investments, upward price adjustment, amount		$ 0		$ 0
Equity investments, downward price adjustment, amount		$ 0		$ 0
Pensare [Member] | Plan [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Warrants, exercise price (in dollars per share) | $ / shares	$ 11.50
Pensare [Member] | Plan [Member] | Common Stock [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Investment, restriction period (in years)	1 year