Schedule of Impact of Adoption on Condensed Consolidated Income Statement (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Disaggregation Of Revenue [Line Items]
Net Revenue before provision for doubtful accounts		$ 2,775,790		$ 8,428,971
Less: Provision for doubtful accounts		233,926		661,893
Net revenues	$ 2,648,913	2,541,864	$ 8,017,782	7,767,078
Other operating expenses	651,442	$ 628,523	1,896,745	$ 1,868,076
Balances Without Adoption ASC 606 | ASU 2014-09
Disaggregation Of Revenue [Line Items]
Net Revenue before provision for doubtful accounts	2,929,710		8,814,635
Less: Provision for doubtful accounts	285,044		807,747
Net revenues	2,644,666		8,006,888
Other operating expenses	647,195		1,885,851
Effect of Change | ASU 2014-09
Disaggregation Of Revenue [Line Items]
Net revenues	4,247		10,894
Other operating expenses	$ 4,247		$ 10,894