Goodwill and Other Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Jul. 01, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Core deposit intangible	$ 51,342		$ 49,772
Less: accumulated amortization	(36,079)		(32,964)
Total intangibles subject to amortization, net	15,263		16,808
Goodwill	142,025	$ 131,312	130,612	$ 123,566	$ 14,527	$ 1,509
Total goodwill and other intangible assets, net	$ 157,288		$ 147,420