Segment Information - Intersegment Activity Eliminated in Arriving at Consolidated Totals was Included in "All Other" Category (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Revenues	$ (4,667,624)	$ (4,455,719)	$ (4,538,434)
Income taxes (benefit)	(595,025)	(575,999)	(627,088)
Net income	(1,079,667)	(1,066,246)	(1,138,480)
Intersegment Activity Eliminated in Consolidated Totals [Member]
Segment Reporting Information [Line Items]
Revenues	(48,972)	(49,800)	(50,128)
Expenses	(13,332)	(12,014)	(16,235)
Income taxes (benefit)	(14,503)	(15,375)	(13,791)
Net income	$ (21,137)	$ (22,411)	$ (20,102)