Investment Securities (Details 2) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Unrealized Losses on Securities Available-for-Sale, Less than 12 Months, Fair Value	$ 796,977	$ 716,081
Unrealized Losses on Securities Available-for-Sale, Less than 12 Months, Gross Unrealized Losses	(30,403)	(3,545)
Unrealized Losses on Securities Available-for-Sale, 12 Months or Longer, Fair Value	74,659	1,756
Unrealized Losses on Securities Available-for-Sale, 12 Months or Longer, Gross Unrealized Losses	(3,191)	(10)
Unrealized Losses on Securities Available-for-Sale, Fair Value	871,636	717,837
Unrealized Losses on Securities Available-for-Sale, Gross Unrealized Losses	(33,594)	(3,555)
Government agency and government-sponsored enterprise pass through securities
Unrealized Losses on Securities Available-for-Sale, Less than 12 Months, Fair Value	109,101	0
Unrealized Losses on Securities Available-for-Sale, Less than 12 Months, Gross Unrealized Losses	(1,375)	0
Unrealized Losses on Securities Available-for-Sale, 12 Months or Longer, Fair Value	0	186
Unrealized Losses on Securities Available-for-Sale, 12 Months or Longer, Gross Unrealized Losses	0	(1)
Unrealized Losses on Securities Available-for-Sale, Fair Value	109,101	186
Unrealized Losses on Securities Available-for-Sale, Gross Unrealized Losses	(1,375)	(1)
Government agency and government-sponsored enterprise collateralized mortgage obligations
Unrealized Losses on Securities Available-for-Sale, Less than 12 Months, Fair Value	263,858	180,071
Unrealized Losses on Securities Available-for-Sale, Less than 12 Months, Gross Unrealized Losses	(6,921)	(572)
Unrealized Losses on Securities Available-for-Sale, 12 Months or Longer, Fair Value	37,560	1,456
Unrealized Losses on Securities Available-for-Sale, 12 Months or Longer, Gross Unrealized Losses	(763)	(7)
Unrealized Losses on Securities Available-for-Sale, Fair Value	301,418	181,527
Unrealized Losses on Securities Available-for-Sale, Gross Unrealized Losses	(7,684)	(579)
Municipal securities
Unrealized Losses on Securities Available-for-Sale, Less than 12 Months, Fair Value	7,521	38,667
Unrealized Losses on Securities Available-for-Sale, Less than 12 Months, Gross Unrealized Losses	(29)	(339)
Unrealized Losses on Securities Available-for-Sale, 12 Months or Longer, Fair Value	0	0
Unrealized Losses on Securities Available-for-Sale, 12 Months or Longer, Gross Unrealized Losses	0	0
Unrealized Losses on Securities Available-for-Sale, Fair Value	7,521	38,667
Unrealized Losses on Securities Available-for-Sale, Gross Unrealized Losses	(29)	(339)
Government agency and government-sponsored enterprise commercial mortgage-backed securities
Unrealized Losses on Securities Available-for-Sale, Less than 12 Months, Fair Value	9,523	214,862
Unrealized Losses on Securities Available-for-Sale, Less than 12 Months, Gross Unrealized Losses	(115)	(537)
Unrealized Losses on Securities Available-for-Sale, 12 Months or Longer, Fair Value	0	0
Unrealized Losses on Securities Available-for-Sale, 12 Months or Longer, Gross Unrealized Losses	0	0
Unrealized Losses on Securities Available-for-Sale, Fair Value	9,523	214,862
Unrealized Losses on Securities Available-for-Sale, Gross Unrealized Losses	(115)	(537)
Asset-backed Securities
Unrealized Losses on Securities Available-for-Sale, Less than 12 Months, Fair Value	171,096	165,575
Unrealized Losses on Securities Available-for-Sale, Less than 12 Months, Gross Unrealized Losses	(7,547)	(1,670)
Unrealized Losses on Securities Available-for-Sale, 12 Months or Longer, Fair Value	36,993	0
Unrealized Losses on Securities Available-for-Sale, 12 Months or Longer, Gross Unrealized Losses	(2,419)	0
Unrealized Losses on Securities Available-for-Sale, Fair Value	208,089	165,575
Unrealized Losses on Securities Available-for-Sale, Gross Unrealized Losses	(9,966)	(1,670)
Collateralized loan obligations
Unrealized Losses on Securities Available-for-Sale, Less than 12 Months, Fair Value	130,082	102,469
Unrealized Losses on Securities Available-for-Sale, Less than 12 Months, Gross Unrealized Losses	(12,062)	(403)
Unrealized Losses on Securities Available-for-Sale, 12 Months or Longer, Fair Value	0	0
Unrealized Losses on Securities Available-for-Sale, 12 Months or Longer, Gross Unrealized Losses	0	0
Unrealized Losses on Securities Available-for-Sale, Fair Value	130,082	102,469
Unrealized Losses on Securities Available-for-Sale, Gross Unrealized Losses	(12,062)	(403)
Private label collateralized mortgage obligations
Unrealized Losses on Securities Available-for-Sale, Less than 12 Months, Fair Value	86,880	9,872
Unrealized Losses on Securities Available-for-Sale, Less than 12 Months, Gross Unrealized Losses	(2,247)	(11)
Unrealized Losses on Securities Available-for-Sale, 12 Months or Longer, Fair Value	105	114
Unrealized Losses on Securities Available-for-Sale, 12 Months or Longer, Gross Unrealized Losses	(8)	(2)
Unrealized Losses on Securities Available-for-Sale, Fair Value	86,985	9,986
Unrealized Losses on Securities Available-for-Sale, Gross Unrealized Losses	(2,255)	(13)
SBA asset-backed securities
Unrealized Losses on Securities Available-for-Sale, Less than 12 Months, Fair Value	1,958	4,565
Unrealized Losses on Securities Available-for-Sale, Less than 12 Months, Gross Unrealized Losses	(65)	(13)
Unrealized Losses on Securities Available-for-Sale, 12 Months or Longer, Fair Value	0	0
Unrealized Losses on Securities Available-for-Sale, 12 Months or Longer, Gross Unrealized Losses	0	0
Unrealized Losses on Securities Available-for-Sale, Fair Value	1,958	4,565
Unrealized Losses on Securities Available-for-Sale, Gross Unrealized Losses	(65)	$ (13)
Corporate debt securities
Unrealized Losses on Securities Available-for-Sale, Less than 12 Months, Fair Value	16,958
Unrealized Losses on Securities Available-for-Sale, Less than 12 Months, Gross Unrealized Losses	(42)
Unrealized Losses on Securities Available-for-Sale, 12 Months or Longer, Fair Value	1
Unrealized Losses on Securities Available-for-Sale, 12 Months or Longer, Gross Unrealized Losses	(1)
Unrealized Losses on Securities Available-for-Sale, Fair Value	16,959
Unrealized Losses on Securities Available-for-Sale, Gross Unrealized Losses	$ (43)