Income Taxes - Deferred Income Tax Assets (Liabilities) (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Allowances and reserves	$ 204,661	$ 211,538
Research and development expenses	193,908	191,057
Loss carryforwards	165,522	150,270
Deferred compensation	78,245	98,832
Tax credit carryforwards	59,426	50,309
Postretirement benefits	47,732	48,648
Intangible assets	9,160	14,035
Other	62,057	71,453
Gross deferred income tax assets	820,711	836,142
Intangible assets	(295,968)	(305,818)
Other	0	(2,905)
Gross deferred income tax liabilities	(295,968)	(308,723)
Deferred income tax asset valuation allowances	(74,125)	(77,334)
Net deferred income tax assets	$ 450,618	$ 450,085