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Employee and Retiree Benefit Plans (Details) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013
Thrift Plan [Member] |  |  |
Defined Contribution Plan Disclosure [Line Items] |  |  |
Company matching contribution (percent) | 100.00% |  |
Employee's maximum contribution matched by Company (percent) | 6.00% |  |
Profit sharing percentage 1 | 5.00% |  |
Profit sharing percentage 2 | 7.00% |  |
Profit sharing percentage 3 | 9.00% |  |
Profit sharing contributions | $ 9,216 | $ 8,879 | $ 4,567
Profit Sharing Plan [Member] |  |  |
Defined Contribution Plan Disclosure [Line Items] |  |  |
Profit sharing contributions | $ 1,848 | $ 1,848 | $ 1,861

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- Definition Defined Contribution Plan, Profit Sharing Percentage 2 + References No definition available. + 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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- Definition Amount of payroll tax expense, compensation, postemployment and benefit-related expenses not elsewhere specified in the taxonomy (such as health plan, profit sharing, incentives, tuition reimbursement, other fringe benefits and perquisites) incurred in the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.4) -URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688 + Details
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