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Deposits (Details) - USD ($) | 12 Months Ended
--- | ---
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
Deposits, by Type [Abstract] |  |  |
Non-interest bearing demand | $ 3,158,300,000 | $ 2,900,000,000 |
Interest bearing: |  |  |
Demand | 2,957,500,000 | 2,787,500,000 |
Savings | 3,247,900,000 | 3,095,400,000 |
Total | 547,600,000 | 432,000,000 |
Time, other | 769,400,000 | 720,000,000 |
Total interest bearing | 7,522,400,000 | 7,034,900,000 |
Total deposits | 10,680,700,000 | 9,934,900,000 |
Brokered time deposits | 24,100,000 | 0 |
Time deposits obtained through Certificate of Deposit Account Registry Service (CDARS) | 87,100,000 | 94,200,000 |
Time deposits of $250,000 or more | 221,000,000 | 182,000,000 |
FDIC deposit insurance limit | 250,000,000 |  |
Time, $100 and Over |  |  |
Due within 3 months or less | 45,000,000 |  |
Due after 3 months and within 6 months | 49,000,000 |  |
Due after 6 months and within 12 months | 217,500,000 |  |
Due within 2020 | 159,700,000 |  |
Total | 547,600,000 | 432,000,000 |
Total Time |  |  |
Due within 3 months or less | 253,800,000 |  |
Due after 3 months and within 6 months | 149,200,000 |  |
Due after 6 months and within 12 months | 420,400,000 |  |
Due within 2020 | 323,700,000 |  |
Total | 1,317,000,000 |  |
Interest expense, time deposits, $100,000 or more | 7,000,000 | $ 4,300,000 | $ 3,700,000
Contractual Maturities, Time Deposits, $100,000 or More, after 2 years | 63,500,000 |  |
Time Deposits Maturities, after Next Two Years | 128,800,000 |  |
Contractual Maturities, Time Deposits, $100,000 or More, after 3 years | 9,800,000 |  |
Time Deposits Maturities, after Next Three Years | 30,300,000 |  |
Contractual Maturities, Time Deposits, $100,000 or More, after 5 years and thereafter | 3,100,000 |  |
Time Deposits Maturities, after Next Five Years and Thereafter | $ 10,800,000 |  |

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- Definition 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. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher SEC -Name Industry Guide -Number 3 -Section V -Paragraph D-E + Details
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- Definition The amount of money in accounts that may bear interest and that the depositor is entitled to withdraw at any time without prior notice. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.12) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
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