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Employee Benefits Employee Benefits - Additional Information (Detail) - USD ($) $ in Millions |  | 3 Months Ended | 12 Months Ended
--- | --- | --- | ---
Jan. 01, 2015 | Mar. 31, 2016 | Dec. 31, 2015
Compensation and Retirement Disclosure [Abstract] |  |  |
Pension plan curtailment gain |  | $ 1.0 |
Period of unrecognized benefits associated with prior year plan amendments that would have been amortized into income |  | 7 years |
Number of consecutive years of employee's compensation |  |  | 5 years
Number of total years of employee's compensation |  |  | 10 years
Expected long-term rate of return on plan assets |  |  | 7.50%
Lump sum death benefit to unmarried beneficiary as percent of accrued benefit payable (percent) | 80.00% |  |

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- Definition Defined Benefit Plan, Lump Sum Death Benefit for Beneficiaries of Unmarried Participants, Percent + References No definition available. + Details
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- Definition Defined Benefit Plan, Unrecognized Benefits Due to Settlements and Curtailments, Period of Recognition + References No definition available. + Details
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- Definition Number Of Consecutive Periods Of Highest Compensation Used To Determine Defined Benefit Pension Plan Benefits + References No definition available. + Details
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- Definition Number Of Periods Used To Determine Defined Benefit Pension Plan Benefits + References No definition available. + Details
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- Definition An assumption as to the rate of return on plan assets reflecting the average rate of earnings expected on the funds invested or to be invested to provide for the benefits included in the benefit obligation. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Expected Long-Term Rate of Return on Plan Assets -URI http://asc.fasb.org/extlink&oid=6512046 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (k)(3) -URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920 + Details
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- Definition Amount of net gain (loss) recognized in net periodic benefit cost due to settlements and curtailments. Curtailments result from an event that significantly reduces the expected years of future service of present employees or eliminates for a significant number of employees the accrual of defined benefits for some or all of their future services. Settlements result from an irrevocable action that relieves the employer (or the plan) of primary responsibility for a benefit obligation and eliminates significant risks related to the obligation and the assets used to effect the settlement. Examples of transactions that constitute a settlement include, but are not limited to, lump-sum cash payments to plan participants in exchange for their rights to receive specified benefits and purchasing nonparticipating annuity contracts to cover vested benefits. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (h)(7) -URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920 + Details
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