Summary of Other Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018
Other Assets [Abstract]
Equity method and other investments	$ 81,836	$ 122,433	$ 80,779	$ 22,325	$ 13,814	$ 12,649
Right of use asset - leases	12,257
Other intangible assets and other	5,098		4,336
Total other assets	$ 99,191		$ 85,115