Business Segment Information - Reconciliation of Total Segment Assets to Total Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting [Abstract]
Total segment assets	$ 4,875,328	$ 4,527,925	$ 4,591,468
Other assets	55,731	51,369
Total assets	$ 4,931,059	$ 4,579,294