Fair Value of Financial Instruments (Other Investments - Pensare) (Narrative) (Details) - Pensare [Member] - Chief Executive Officer [Member] - USD ($) $ / shares in Units, $ in Millions		3 Months Ended
	Mar. 31, 2018	Sep. 30, 2017
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity investment and warrants, amount paid (in dollars)		$ 2.0
Equity investment, ownership percentage	4.00%
Plan [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Warrants, exercise price (in dollars per share)	$ 11.50
Plan [Member] | Common Stock [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Investment, restriction period (in years)	1 year
Warrants [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Derivative instruments, number held	2,000,000