Composition of Corporate and Unallocated Costs (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Corporate and unallocated costs	$ 658,659	$ 697,834	$ 568,336
Cost of sales
Segment Reporting Information [Line Items]
Corporate and unallocated costs	90,791	150,588	56,311
Selling, general and administrative expenses
Segment Reporting Information [Line Items]
Corporate and unallocated costs	389,753	375,747	349,993
Research and development expenses
Segment Reporting Information [Line Items]
Corporate and unallocated costs	$ 178,115	$ 171,499	$ 162,032