Mergers and Acquisitions (Pro Forma Information) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Business Acquisition
Net interest and other income	$ 492,323	$ 654,962	$ 361,695
Net income	$ 115,847	$ 142,504	$ 79,455
Earnings per share:
Basic (in dollars per share)	$ 1.65	$ 2.03	$ 2.17
Diluted (in dollars per share)	$ 1.62	$ 2.01	$ 2.16