Deposits (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Deposits [Abstract]
Interest-bearing Domestic Deposit, Brokered	$ 0	$ 0
Deposits, by Type [Abstract]
Non-interest bearing demand	1,906,257	1,823,716
Interest bearing:
Demand	2,276,494	2,178,373
Savings	2,141,761	1,955,256
Time, $100 and over	461,368	487,372
Time, other	590,230	644,220
Total interest bearing	5,469,853	5,265,221
Total deposits	7,376,110	7,088,937
Time deposits obtained through Certificate of Deposit Account Registry Service (CDARS)	25,723	38,336
Contractual Maturities, Time Deposits, $100,000 or More [Abstract]
2015, Time, $100 and Over	121,615
2016, Time, $100 and Over	80,224
2017, Time, $100 and Over	120,533
2018, Time, $100 and Over	138,996
Time Deposits, $100,000 or More	461,368	487,372
Time Deposits, Fiscal Year Maturity [Abstract]
2015, Time	288,325
2016, Time	168,225
2017, Time	251,238
2018, Time	343,810
Time Deposits	1,051,598
Interest expense, time deposits, $100,000 or more	3,684	3,739	$ 4,003
Time Deposits, $250,000 or More	208,525	$ 222,912
FDIC Deposit Insurance Limit	$ 250

Contractual Maturities, Time Deposits, Six Months through Twelve Months

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Contractual Maturities, Time Deposits, Three Months or Less

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Contractual Maturities, Time Deposits, Three Months through Six Months

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FDIC Deposit Insurance Limit

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Time Deposits, $250,000 or More

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Time Deposits Obtained, Certificate of Deposit Account Registry Service

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Amount of time deposit liabilities, including certificates of deposit, in denominations of $100,000 or more, maturing after twelve months from the balance sheet date.

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-Publisher SEC
-Name Industry Guide
-Number 3
-Section V
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Amount of time deposit liabilities, including certificates of deposit, in denominations of $100,000 or more, maturing within six to twelve months after the balance sheet date.

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Amount of time deposit liabilities, including certificates of deposit, in denominations of $100,000 or more, maturing within three months or fewer from the balance sheet date.

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Amount of time deposit liabilities, including certificates of deposit, in denominations of $100,000 or more, maturing within three to six months after the balance sheet date.

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The amount of money in accounts that may bear interest and that the depositor is entitled to withdraw at any time without prior notice.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
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The aggregate of all deposit liabilities held by the entity, including foreign and domestic, interest and noninterest bearing; may include demand deposits, saving deposits, Negotiable Order of Withdrawal (NOW) and time deposits among others.

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Amount of interest bearing deposits with no stated maturity, which may include passbook and statement savings accounts and money-market deposit accounts (MMDAs).

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The aggregate of all domestic and foreign interest-bearing deposit liabilities.

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Amount of interest-bearing domestic third-party deposits placed by or through the assistance of a deposit broker, also known as brokered deposit liabilities.

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Interest expense incurred on time deposits, including certificates of deposits, of $100,000 or more in domestic offices.

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The aggregate amount of all domestic and foreign noninterest-bearing deposits liabilities held by the entity.

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Amount of time deposit liabilities, including certificates of deposit.

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Amount of time deposit liabilities, including certificates of deposit, in denominations of $100,000 or more.

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Amount of time deposit liabilities, including certificates of deposit, in denominations of less than $100,000.

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Amount of time deposits maturing after 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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