Goodwill - Roll Forward of Goodwill (Detail) - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
		Sep. 30, 2019	Jun. 30, 2019
Goodwill [Roll Forward]
Balance		$ 3,336,079	$ 2,620,835
Goodwill acquired	[1]	4,493	719,203
Foreign currency translation		(3,519)	(3,959)
Balance		3,337,053	3,336,079
Domestic
Goodwill [Roll Forward]
Balance		3,224,685	2,514,520
Goodwill acquired	[1]	5,663	710,165
Balance		3,230,348	3,224,685
International
Goodwill [Roll Forward]
Balance		111,394	106,315
Goodwill acquired	[1]	(1,170)	9,038
Foreign currency translation		(3,519)	(3,959)
Balance		$ 106,705	$ 111,394

[1] Includes goodwill initially allocated to new business combinations as well as measurement period adjustments.