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Employee Benefit Plans - Additional Information (Detail) - USD ($) shares in Thousands, $ in Millions | 3 Months Ended | 6 Months Ended
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Jun. 30, 2017 | Jun. 30, 2017
Minimum |  |
Compensation and Retirement Disclosure [Abstract] |  |
Percentage of pre-tax earnings paid for profit sharing plan |  | 5.00%
Maximum |  |
Compensation and Retirement Disclosure [Abstract] |  |
Percentage of pre-tax earnings paid for profit sharing plan |  | 20.00%
Pension Benefits |  |
Compensation and Retirement Disclosure [Abstract] |  |
Employer contribution to tax-qualified defined benefit pension plans | $ 160 | $ 240
RSUs |  |
Compensation and Retirement Disclosure [Abstract] |  |
Share-based compensation, other than options, awards granted |  | 1,500
Share-based compensation, vesting period |  | 3 years
Performance Shares |  |
Compensation and Retirement Disclosure [Abstract] |  |
Share-based compensation, vesting period |  | 3 years
Share-Based Compensation, vesting date |  | Dec. 31, 2019
Number of days used to compute performance period average closing price of restricted stock units |  | 20 days
Stock Options |  |
Compensation and Retirement Disclosure [Abstract] |  |
Share-based compensation, option awards granted |  | 36
Time Vested Restricted Stock Units RSU |  |
Compensation and Retirement Disclosure [Abstract] |  |
Share-based compensation, other than options, awards granted |  | 900
Performance Based Restricted Stock Units RSU |  |
Compensation and Retirement Disclosure [Abstract] |  |
Share-based compensation, other than options, awards granted |  | 600

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- Definition The time period over which the stock closing prices are averaged to arrive at a per-share valuation for equity based awards such as Restricted Stock Units, Performance Share and other equity based awards. + References No definition available. + Details
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- Definition Profit Sharing Plan, Percentage of Pre-Tax Earnings Paid + References No definition available. + Details
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- Definition Amount of contribution received by defined benefit plan from employer which increases plan assets. + 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 (d)(5)(ii) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 6 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e2709-114920 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b)(3) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(5)(iv)(01) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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- Definition Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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- Definition The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(1) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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- Definition Net number of share options (or share units) granted during the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(1) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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