Investment Securities - Contractual Maturity (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Amortized Cost
Due after one year through five years	$ 30,442
Due after ten years	63,972
Total contractual maturities	94,414
Amortized Cost	5,025,433	$ 4,080,663
Fair Value
Due after one year through five years	30,941
Due after ten years	63,977
Total contractual maturities	94,918
Fair value	5,135,775	4,075,644
Mortgage-backed securities:
Amortized Cost
Mortgaged-backed securities and collateralized mortgage obligations	1,524,986
Fair Value
Mortgaged-backed securities and collateralized mortgage obligations	1,576,204
Residential - Government agency
Amortized Cost
Mortgaged-backed securities and collateralized mortgage obligations	224,764
Amortized Cost	224,764	290,131
Fair Value
Mortgaged-backed securities and collateralized mortgage obligations	232,617
Fair value	232,617	291,209
Residential - Government-sponsored enterprises
Amortized Cost
Mortgaged-backed securities and collateralized mortgage obligations	375,118
Amortized Cost	375,118	395,039
Fair Value
Mortgaged-backed securities and collateralized mortgage obligations	390,912
Fair value	390,912	399,492
Commercial - Government agency
Amortized Cost
Mortgaged-backed securities and collateralized mortgage obligations	612,811
Amortized Cost	612,811
Fair Value
Mortgaged-backed securities and collateralized mortgage obligations	629,679
Fair value	629,679
Commercial - Government-sponsored enterprises
Amortized Cost
Mortgaged-backed securities and collateralized mortgage obligations	312,293
Amortized Cost	312,293	101,798
Fair Value
Mortgaged-backed securities and collateralized mortgage obligations	322,996
Fair value	322,996	101,719
Collateralized mortgage obligations
Amortized Cost
Mortgaged-backed securities and collateralized mortgage obligations	3,406,033
Fair Value
Mortgaged-backed securities and collateralized mortgage obligations	3,464,653
Government agency
Amortized Cost
Mortgaged-backed securities and collateralized mortgage obligations	1,887,701
Amortized Cost	1,887,701	2,390,143
Fair Value
Mortgaged-backed securities and collateralized mortgage obligations	1,926,584
Fair value	1,926,584	2,381,278
Government-sponsored enterprises
Amortized Cost
Mortgaged-backed securities and collateralized mortgage obligations	1,518,332
Amortized Cost	1,518,332	772,023
Fair Value
Mortgaged-backed securities and collateralized mortgage obligations	1,538,069
Fair value	$ 1,538,069	$ 770,619

Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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