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Stock-Based Compensation Plans - 2013 Omnibus Equity Incentive Plan - Additional Information (Detail) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Vested shares | 400,616 | 333,724 |
2013 Omnibus Equity Incentive Plan [Member] | Options [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Number of shares issued under compensation plan | 0 |  |
Number of shares outstanding under compensation plan | 0 |  |
2013 Omnibus Equity Incentive Plan [Member] | Restricted Stock Awards [Member] | Minimum [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Vesting period | 1 year |  |
2013 Omnibus Equity Incentive Plan [Member] | Restricted Stock Awards [Member] | Maximum [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Vesting period | 3 years |  |
2013 Omnibus Equity Incentive Plan [Member] | Restricted Stock Units [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Vesting period | 5 years |  |
Vested shares | 378,194 |  |
Number of common stock shares withheld to pay employee statutory withholding taxes | 73,690 |  |
2013 Omnibus Equity Incentive Plan [Member] | SARs [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Number of shares issued under compensation plan | 0 |  |
Number of shares outstanding under compensation plan | 0 |  |
2013 Omnibus Equity Incentive Plan [Member] | Performance Shares [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Number of shares issued under compensation plan | 0 |  |
Number of shares outstanding under compensation plan | 0 |  |
2013 Omnibus Equity Incentive Plan [Member] | Performance Units [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Number of shares issued under compensation plan | 0 |  |
Number of shares outstanding under compensation plan | 0 |  |
2013 Omnibus Equity Incentive Plan [Member] | Deferred stock units [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Vested shares | 0 |  |
Fair value of vested, during period | $ 0.0 | $ 8.3 | $ 10.2
Fully vested deferred stock units remaining outstanding | 341,566 | 341,566 | 578,618
2013 Omnibus Equity Incentive Plan [Member] | Restricted Stock Units and Restricted Stock Awards [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Fair value of vested, during period | $ 14.6 | $ 11.1 | $ 7.8

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- Definition Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
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