Significant Accounting Policies - Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of cash flows specific transaction amounts [Abstract]
Income taxes paid	$ 24,809	$ 12,435	$ 7,371
Interest paid on deposits and borrowings	83,997	66,358	41,472
Noncash transfers from loans to other real estate	8,598	$ 12,115	8,760
Investment in tax credit partnership not funded	5,000
Financing right-of-use assets resulting from lease liabilities	9,326
Operating right-of-use assets resulting from lease liabilities	$ 31,182
Transfer of long-term FHLB advances to short-term			250,038
Assets acquired in business combination			196,265
Liabilities assumed in business combination			$ 184,949