Summary of Revenues Disaggregated Based on Timing of Revenue Recognition (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]
Total revenues		$ 889,053	$ 751,195	$ 1,669,024	$ 1,530,805
U.S. Operating Segment
Disaggregation of Revenue [Line Items]
Total revenues	[1]	709,074		1,305,417
International Operating Segment
Disaggregation of Revenue [Line Items]
Total revenues		179,979		363,607
Goods and Services Transferred at a Point in Time
Disaggregation of Revenue [Line Items]
Total revenues		847,813		1,589,788
Goods and Services Transferred at a Point in Time | U.S. Operating Segment
Disaggregation of Revenue [Line Items]
Total revenues	[1]	686,463		1,262,289
Goods and Services Transferred at a Point in Time | International Operating Segment
Disaggregation of Revenue [Line Items]
Total revenues		161,350		327,499
Goods and Services Transferred Over Time
Disaggregation of Revenue [Line Items]
Total revenues		41,240		79,236
Goods and Services Transferred Over Time | U.S. Operating Segment
Disaggregation of Revenue [Line Items]
Total revenues	[1]	22,611		43,128
Goods and Services Transferred Over Time | International Operating Segment
Disaggregation of Revenue [Line Items]
Total revenues		$ 18,629		$ 36,108

[1] U.S. segment revenues include eliminations of intercompany transactions with the international operating segment. See Note 15 for additional information on intercompany eliminations.