Schedule of Impact of Adoption on Condensed Consolidated Income Statement (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Disaggregation Of Revenue [Line Items]
Net Revenue before provision for doubtful accounts		$ 2,827,709		$ 5,653,181
Less: Provision for doubtful accounts		215,353		427,967
Net revenues	$ 2,681,353	2,612,356	$ 5,368,869	5,225,214
Other operating expenses	624,484	$ 632,193	1,245,303	$ 1,239,553
Balances Without Adoption ASC 606 | ASU 2014-09
Disaggregation Of Revenue [Line Items]
Net Revenue before provision for doubtful accounts	2,953,398		5,884,925
Less: Provision for doubtful accounts	276,160		522,703
Net revenues	2,677,238		5,362,222
Other operating expenses	620,369		1,238,656
Effect of Change | ASU 2014-09
Disaggregation Of Revenue [Line Items]
Net revenues	4,115		6,647
Other operating expenses	$ 4,115		$ 6,647