Summary of Significant Accounting Policies (Narrative) (Details)	12 Months Ended
	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Percentage holding required to account investments under non-marketable equity investments	20.00%
Building [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	40 years
Leasehold Improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	10 years
Software, Equipment, Furniture and Fixtures [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	7 years
Software, Equipment, Furniture and Fixtures [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	3 years