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Stock-Based Compensation (Textuals) (Details) | 12 Months Ended
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Dec. 31, 2016 USD ($) plan $ / shares shares | Dec. 31, 2015 $ / shares shares | Dec. 31, 2014 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Share-based Compensation, Executive Retirements | $ | $ 10,400,000 |  |
Shares available for grant/issuance | 5,334,471 |  |
Unrecognized compensation expense for all nonvested awards | $ | $ 16,200,000 |  |
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition | 1 year 8 months |  |
Employee Stock Option [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Vesting period | 4 years |  |
Awards, expiration period | 10 years |  |
Number of shares reduced for each award granted | 1 |  |
Stock Appreciation Rights (SARs) [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Vesting period | 4 years |  |
Awards, expiration period | 10 years |  |
Award Types Other than Stock Options and Stock Appreciation Rights [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Number of shares reduced for each award granted | 2.5 |  |
Performance-Vesting Shares [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | 115,035 | 147,908 | 133,823
Granted at target level | $ / shares | $ 60.47 | $ 55.49 | $ 47.21
Employee Stock Purchase Plan (ESPP) [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Shares available for grant/issuance | 4,000,000 |  |
Percentage of current market price for sales to eligible employees | 85.00% |  |
Limitation on payroll deductions of employee's base salary, percent | 25.00% |  |
Limitation on payroll deductions of employee's base salary, amount | $ | $ 25,000 |  |
Maximum number of shares per employee | 2,000 |  |
Maximum number of shares per employee, per year | 8,000 |  |
Purchases of shares | 60,839 | 61,757 | 76,751
Restricted Stock [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | 1,393 | 41,458 |
Granted at target level | $ / shares | $ 71.79 | $ 57.89 |
Annual Incentive Plan [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | 2,400 | 1,500 | 4,200
Vesting period | 4 years |  |
Granted at target level | $ / shares | $ 59.64 | $ 51.53 | $ 48.69
Performance-Vesting Units [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | 419 | 1,386 | 1,584
Granted at target level | $ / shares | $ 59.64 | $ 54.14 | $ 47.34
Minimum [Member] | Performance-Vesting Shares [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Actual payout range | 0.00% |  |
Minimum [Member] | Performance-Vesting Units [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Actual payout range | 0.00% |  |
Maximum [Member] | Performance-Vesting Shares [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Actual payout range | 200.00% |  |
Maximum [Member] | Performance-Vesting Units [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Actual payout range | 200.00% |  |
Deferred Compensation Plans [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Deferred Compensation Arrangement with Individual, Conversion Unit | 1 |  |
Number of deferred compensation plans | plan | 2 |  |
Number of deferred stock units | 388,287 |  |
Number of deferred stock units payable in cash | 24,296 |  |
Deferred Compensation Plans [Member] | Non-Employee Directors [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | 20,077 |  |
Granted at target level | $ / shares | $ 71.47 |  |

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- Definition Unrecognized cost of unvested share-based compensation awards. + 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 (i) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, 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 (i) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + 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=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 weighted average fair value at grant date for nonvested equity-based awards issued 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 Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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- Definition The highest percentage of annual salary that an employee is permitted to utilize with respect to the 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 -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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