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Stock-Based Compensation - Schedule of Restricted Stock Unit Programs Outstanding (Detail) - shares | 12 Months Ended
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Dec. 31, 2015 | Dec. 31, 2014
Equity Classified RSUs [Member] |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |
Number of options outstanding, Beginning Balance | 985,278 | 1,263,709
Granted | 356,422 | 363,053
Dividend equivalents | 1,633 | 1,678
Redeemed | (495,627) | (643,162)
Number of options outstanding, Ending Balance | 847,706 | 985,278
Liability Classified RSUs [Member] |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |
Number of options outstanding, Beginning Balance | 46,052 | 60,238
Granted | 15,922 | 18,050
Dividend equivalents | 1,094 | 1,132
Forfeitures |  | (820)
Redeemed | (28,236) | (32,548)
Number of options outstanding, Ending Balance | 34,832 | 46,052
Liability/Equity Classified DSUs [Member] |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |
Number of options outstanding, Beginning Balance | 303,261 | 254,894
Granted | 43,955 | 44,272
Dividend equivalents | 5,468 | 4,095
Number of options outstanding, Ending Balance | 352,684 | 303,261
Release of Restricted Stock Units [Member] |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |
Number of options outstanding, Beginning Balance | 1,334,591 | 1,578,841
Granted | 416,299 | 425,375
Dividend equivalents | 8,195 | 6,905
Forfeitures |  | (820)
Redeemed | (523,863) | (675,710)
Number of options outstanding, Ending Balance | 1,235,222 | 1,334,591

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- Definition Share based compensation arrangement by share based payment award equity instruments other than options dividend equivalents in period. + References No definition available. + Details
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- Definition Share based compensation arrangement by share based payment award equity instruments other than options redeemed in period. + References No definition available. + Details
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- Definition The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting 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)(3) -URI http://asc.fasb.org/extlink&oid=6415400&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=6415400&loc=d3e5070-113901 + Details
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- Definition The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date. + 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)(i)-(ii) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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