General Information - Retrospective Effect of Adoption that Impacted on Presentation of Deferred Debt Issuance Costs (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other assets	$ 139,135	$ 101,485
Long-term debt	$ 1,980,884	1,979,778
Scenario, Previously Reported [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other assets		116,480
Long-term debt		1,994,773
Restatement Adjustment [Member] | Deferred Debt Issuance Costs [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other assets		(14,995)
Long-term debt		$ (14,995)