Derivative Financial Instruments - Summary of Effect of Derivative Financial Instruments on Consolidated Statements of Operations (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivatives	$ 1,855	$ 24,011
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income	152	388
Net Investment [Member] | Foreign Currency Contracts [Member] | Interest Expense [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivatives	1,763	23,782
Cash Flow Hedges [Member] | Interest Rate Swaps/Derivatives [Member] | Interest Expense [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income	152,000	388,000
Cash Flow Hedges [Member] | Interest Rate Swaps/Derivatives [Member] | Interest Income (Expense) [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivatives	92	228
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income	$ 152	$ 388