SECURITIES (Amortized Cost And Estimated Fair Value Of Available-For-Sale Securities By Contractual Maturity) (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015
SECURITIES [Abstract]
Maturing in one year or less, Amortized Cost	$ 380,547
Maturing after one year through five years, Amortized Cost	1,023,283
Maturing after five years through ten years, Amortized Cost	49,906
Maturing after ten years, Amortized Cost	241,809
Mortgage-backed securities, Amortized Cost	365,417
Amortized Cost	2,060,962	$ 2,059,445	$ 2,218,468
Maturing in one year or less, Estimated Fair Value	381,075
Maturing after one year through five years, Estimated Fair Value	1,033,003
Maturing after five years through ten years, Estimated Fair Value	53,281
Maturing after ten years, Estimated Fair Value	262,871
Mortgage-backed securities, Estimated Fair Value	373,653
Estimated Fair Value	$ 2,103,883	$ 2,082,329	$ 2,251,153
Maturing in one year or less, Weighted Average Yield	0.91%
Maturing after one year through five years, Weighted Average Yield	1.36%
Maturing after five years through ten years, Weighted Average Yield	5.77%
Maturing after ten years, Weighted Average Yield	5.72%
Mortgage-backed securities, Weighted Average Yield	2.08%