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Employee Benefit Plans (Narrative) (Details) | 12 Months Ended
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Dec. 31, 2019 USD ($) executive | Dec. 31, 2018 USD ($) executive | Dec. 31, 2017 USD ($) executive
Employee Benefit Plan [Line Items] |  |  |
Maximum employee contribution (as a percent) | 80.00% |  |
Company match percentage (as a percent) | 100.00% |  |
Percentage of employee pay that Company matches (as a percent) | 6.00% |  |
Matching contribution annual vesting rate (as a percent) | 20.00% |  |
Matching contribution, vesting period | 5 years |  |
Employer's contribution | $ 14,000,000.0 | $ 9,900,000 | $ 8,900,000
Supplemental Executive Retirement Plan (SERP) |  |  |
Employee Benefit Plan [Line Items] |  |  |
Additional benefits to be accrued for | $ 0 |  |
Number of executives remaining under the SERP | executive | 1 | 1 | 1
Accrued benefit expense | $ 333,000 | $ 332,000 | $ 331,000
Benefit obligation | $ 4,200,000 | $ 4,200,000 |

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- Definition Employee Benefit Plan [Line Items] + References No definition available. + Details
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- Definition Amount of actuarial present value of benefits attributed to service rendered by employee for defined benefit plan. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 + Details
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- Definition Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan. + References No definition available. + Details
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- Details
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