Revolving Credit Facility and Bank Borrowings (Notes Payable) (Details) - Notes Payable [Member]	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Weighted average interest rate (percent)	2.30%	2.41%
Minimum [Member]
Debt Instrument [Line Items]
Notes payable stated interest rate (percent)	1.95%
Maximum [Member]
Debt Instrument [Line Items]
Notes payable stated interest rate (percent)	2.826%