Acquisition Activity - Pro Forma Information (Details) - Sabadell United - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2017
Business Acquisition [Line Items]
Net interest income	$ 224,931	$ 456,018
Non-interest income	55,094	109,849
Net income	$ 89,851	$ 133,143