Securities (Schedule of Contractual Maturities of Investment Securities Available for Sale) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Abstract]
Due within one year, Amortized Cost	$ 77,363
Due after one year through five years, Amortized Cost	416,556
Due after five years through ten years, Amortized Cost	2,007,225
Due after ten years, Amortized Cost	1,201,952
Total investment securities available-for-sale, Amortized Cost	3,703,096
Due within one year, Fair Value	77,538
Due after one year through five years, Fair Value	421,363
Due after five years through ten years, Fair Value	2,041,751
Due after ten years, Fair Value	1,205,490
Total investment securities available-for-sale, Fair Value	$ 3,746,142	$ 3,167,448

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

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in sixth fiscal year through tenth fiscal year following latest fiscal year. Excludes interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date.

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Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in sixth through tenth fiscal year following latest fiscal year. Excludes interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date.

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in second through fifth fiscal year following latest fiscal year. Excludes interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date.

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