Derivative Financial Instruments - Summary of Effect of Derivative Financial Instruments on the Consolidated Statements of Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Designated as Hedging Instrument | Interest Rate Swaps and Collars
Derivative Instruments Gain Loss [Line Items]
Amount of Gain or (Loss) Recognized in OCI on Derivative	$ 1,567	$ 2,317
Location of Gain or (Loss) Reclassified from Accumulated OCI into Income	Interest expense
Amount of Gain or (Loss) Reclassified from Accumulated OCI into Net Income	$ 577	$ 112
Not Designated as Hedging Instrument | Foreign Currency Forward Contracts
Derivative Instruments Gain Loss [Line Items]
Location of Gain or (Loss) Reclassified from Accumulated OCI into Income	Foreign currency (loss) gain, net
Amount of Gain or (Loss) Recognized in Net Income	$ 1,491