Acquisitions - Additional Information (Detail) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
	Sep. 13, 2021	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Business Acquisition [Line Items]
Operating revenues		$ 549,842	$ 517,099	$ 498,180	$ 478,423	$ 443,661	$ 425,333	$ 409,616	$ 416,780	$ 2,043,544	$ 1,695,390	$ 1,557,796
ASU 2021-08 [Member]
Business Acquisition [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted		true								true
Change in accounting principle, accounting standards update, early adoption		true								true
RCA [Member]
Business Acquisition [Line Items]
Date of acquisition	Sep. 13, 2021
Aggregate cash purchase price	$ 949,000
Operating revenues										$ 22,100