Acquisitions - Pro Forma Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Business Combinations [Abstract]
Net interest and other income	$ 70,463	$ 70,193	$ 60,538	$ 203,018	$ 179,958
Net income	$ 20,232	$ 14,176	$ 13,410	$ 44,492	$ 38,562
Basic earnings per share (in dollars per share)	$ 0.51	$ 0.36	$ 0.34	$ 1.12	$ 0.98
Diluted earnings per share (in dollars per share)	$ 0.50	$ 0.35	$ 0.34	$ 1.10	$ 0.97