Fair Value Measurements - Schedule of Effect of Company Interest Rate Swaps in Consolidated Statement of Comprehensive Income (Detail) - Cash Flow Hedging [Member] - Interest Rate Swap [Member] - Interest Expense - Net [Member] $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($)
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Amount of Gain Recognized in Accumulated Other Comprehensive Loss, net of tax	$ 8,814
Amount of Loss Reclassified from Accumulated Other Comprehensive Loss to Income, net of tax	$ 226