Significant Accounting Policies (Property and Equipment) (Details)	12 Months Ended
	Dec. 31, 2016
Software and Software Development Costs [Member]
Property, Plant and Equipment [Line Items]
Useful life	3 years
Building [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life	40 years
Computer Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life	10 years
Computer Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful life	3 years