Acquisitions - Pro Forma Information (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Business Combinations [Abstract]
Net interest and other income	$ 473,748	$ 465,400	$ 378,894
Net income	$ 133,565	$ 96,758	$ 104,908
Basic earnings per share (in dollars per share)	$ 2.16	$ 1.58	$ 1.71
Diluted earnings per share (in dollars per share)	$ 2.14	$ 1.56	$ 1.70