Acquisition Activity - Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Business Acquisition [Line Items]
Interest income	$ 655,788	$ 632,762
Noninterest income	244,687	253,205
Noninterest expense	549,312	592,144
Income tax expense	45,846	25,431
Net income	$ 120,823	39,267
As Previously Reported
Business Acquisition [Line Items]
Interest income		632,761
Noninterest income		226,579
Noninterest expense		573,119
Income tax expense		22,618
Net income		34,478
Retrospective Adjustments
Business Acquisition [Line Items]
Interest income		1
Noninterest income		26,626
Noninterest expense		19,025
Income tax expense		2,813
Net income		$ 4,789