Securities - Schedule of Unrealized Loss and Fair Value on Investments (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Jan. 01, 2020	Dec. 31, 2019
Fair Value
Less Than 12 Months	$ 146,666		$ 312,988
12 Months or Longer	115,778		214,951
Total	262,444		527,939
Unrealized Losses
Less Than 12 Months	(9,118)		(2,041)
12 Months or Longer	(13,057)		(2,506)
Total	(22,175)		(4,547)
U.S. Treasury securities and obligations of U.S. government agencies
Fair Value
Less Than 12 Months			758
12 Months or Longer			0
Total			758
Unrealized Losses
Less Than 12 Months			(4)
12 Months or Longer			0
Total			(4)
Mortgage-backed securities and collateralized mortgage obligations of U.S. government sponsored entities
Fair Value
Less Than 12 Months	37,338		220,057
12 Months or Longer	363		104,184
Total	37,701		324,241
Unrealized Losses
Less Than 12 Months	(239)		(1,461)
12 Months or Longer	(13)		(1,923)
Total	(252)		(3,384)
Private mortgage-backed securities and collateralized mortgage obligations
Fair Value
Less Than 12 Months	37,775		2,978
12 Months or Longer	0		0
Total	37,775		2,978
Unrealized Losses
Less Than 12 Months	(2,410)		(5)
12 Months or Longer	0		0
Total	(2,410)		(5)
Collateralized loan obligations
Fair Value
Less Than 12 Months	70,314		88,680
12 Months or Longer	115,415		110,767
Total	185,729		199,447
Unrealized Losses
Less Than 12 Months	(6,465)		(570)
12 Months or Longer	(13,044)		(583)
Total	(19,509)	$ (1,200)	(1,153)
Obligations of state and political subdivisions
Fair Value
Less Than 12 Months	1,239		515
12 Months or Longer	0		0
Total	1,239		515
Unrealized Losses
Less Than 12 Months	(4)		(1)
12 Months or Longer	0		0
Total	$ (4)		$ (1)