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Stock-Based Compensation - Schedule of Restricted Stock Unit Programs Outstanding (Detail) | 12 Months Ended
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Dec. 31, 2013 | Dec. 31, 2012 | Dec. 31, 2011
Equity Classified RSUs [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Number of options outstanding, Beginning Balance | 605,430 | 367,726 | 181,732
Granted | 224,841 | 320,131 | 208,458
Dividend equivalents | 1,262 | 1,895 | 2,022
Redeemed | (199,679) | (84,322) | (24,486)
Number of options outstanding, Ending Balance | 631,854 | 605,430 | 367,726
Liability Classified RSUs [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Number of options outstanding, Beginning Balance | 20,099 | 29,806 | 34,242
Granted | 13,825 | 15,364 | 4,150
Dividend equivalents | 624 | 1,133 | 946
Redeemed | (4,429) | (26,204) | (9,532)
Number of options outstanding, Ending Balance | 30,119 | 20,099 | 29,806
Liability Classified DSUs [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Number of options outstanding, Beginning Balance | 206,923 | 198,446 | 186,348
Granted | 30,716 | 37,456 | 22,669
Dividend equivalents | 2,815 | 5,145 | 4,696
Redeemed | (113,007) | (34,124) | (15,267)
Number of options outstanding, Ending Balance | 127,447 | 206,923 | 198,446
Release of Restricted Stock Units [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Number of options outstanding, Beginning Balance | 832,452 | 595,978 | 402,322
Granted | 269,382 | 372,951 | 235,277
Dividend equivalents | 4,701 | 8,173 | 7,664
Redeemed | (317,115) | (144,650) | (49,285)
Number of options outstanding, Ending Balance | 789,420 | 832,452 | 595,978

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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 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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- Details
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