Debt and Short-Term Borrowings - Interest Rate Swap (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Derivative [Line Items]
Notional Amount	$ 200,000	$ 200,000
Reclassified losses from accumulated other comprehensive income loss	1,600
Other long-term assets	214	0
Other long-term liabilities	0	$ 1,964
Reclassification from accumulated comprehensive loss over the next 12 months	$ 900
1-month LIBOR
Derivative [Line Items]
Fixed Rate	1.9225%	1.9225%