Premises and Equipment Components of Premises and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Computer software	$ 189,867	$ 170,625
Computer hardware	56,215	41,856
Leasehold improvements	70,909	60,339
Furniture and equipment	31,886	28,645
Total	348,877	301,465
Accumulated depreciation and amortization	(228,194)	(198,840)
Premises and equipment, net	$ 120,683	$ 102,625