Deposits and Related Interest (Maturities of Time Deposits) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Maturities of Time Deposits [Abstract]
Time Deposit Maturities Less Than Three Month	$ 316,382	$ 277,621
Time Deposit Maturities Three To Twelve Month	508,285	534,548
Total Time deposits	824,667	812,169
Time Deposit Maturities, Year Two	470,670	488,440
Time Deposit Maturities, Year Three	137,016	154,545
Time Deposit Maturities, Year Four	36,125	29,701
Time Deposit Maturities, Year Five	38,623	41,949
Certificates of deposit	$ 1,507,101	$ 1,526,804

Time Deposit Maturities Less Than Three Month

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- Definition

Time Deposit Maturities Three To Twelve Month

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No definition available.

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- Definition

Total Time Deposits Excluding Equity Indexes Options

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No definition available.

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- References

No definition available.

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- Definition

Amount of time deposits maturing in the fifth fiscal year following the latest fiscal year. Time deposits include, but are not limited to, certificates of deposits. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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- Definition

Amount of time deposits maturing in the fourth fiscal year following the latest fiscal year. Time deposits include, but are not limited to, certificates of deposits. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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- Definition

Amount of time deposits maturing in the next fiscal year following the latest fiscal year. Time deposits include, but are not limited to, certificates of deposits. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6802200&loc=d3e1835-112601

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Industry Guide
-Number 3
-Section V
-Paragraph D-E

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Amount of time deposits maturing in the third fiscal year following the latest fiscal year. Time deposits include, but are not limited to, certificates of deposits. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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- Definition

Amount of time deposits maturing in the second fiscal year following the latest fiscal year. Time deposits include, but are not limited to, certificates of deposits. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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