Mergers and Acquisitions - Amounts Recorded on Consolidated Balance Sheets in Conjunction with Acquisition (Detail) - USD ($) $ in Thousands		Mar. 11, 2017	Feb. 13, 2016		Mar. 31, 2017	Dec. 31, 2016	Apr. 22, 2016
Business Acquisition [Line Items]
Goodwill recognized					$ 2,250,305	$ 1,032,129
Yadkin Financial Corporation (YDKN) [Member]
Business Acquisition [Line Items]
Fair value of consideration paid		$ 1,783,366
Cash and cash equivalents		197,682
Securities		940,634
Loans		5,116,497
Core deposit and other intangible assets		69,555
Fixed and other assets		460,752
Total identifiable assets acquired		6,785,120
Deposits		5,176,758
Borrowings		969,385
Other liabilities		73,652
Total liabilities assumed		6,219,795
Fair value of net identifiable assets acquired		565,325
Goodwill recognized	[1]	1,218,041
Fifth Third Bank Branches [Member]
Business Acquisition [Line Items]
Cash and cash equivalents							$ 198,872
Loans							95,354
Core deposit and other intangible assets							4,129
Fixed and other assets							14,069
Total identifiable assets acquired							312,424
Deposits							302,529
Other liabilities							24,041
Total liabilities assumed							326,570
Fair value of net identifiable assets acquired							(14,146)
Goodwill recognized	[1]						$ 14,146
Metro Bancorp Inc [Member]
Business Acquisition [Line Items]
Fair value of consideration paid			$ 404,242
Cash and cash equivalents			46,890
Securities			722,980
Loans			1,862,447
Core deposit and other intangible assets			24,163
Fixed and other assets			127,185
Total identifiable assets acquired			2,783,665
Deposits			2,328,238
Borrowings			227,539
Other liabilities			8,700
Total liabilities assumed			2,564,477
Fair value of net identifiable assets acquired			219,188
Goodwill recognized		$ 1,200,000	$ 185,054	[1]

[1] All of the goodwill for these transactions has been recorded in the Community Banking Segment.