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Stock-Based Compensation (Textuals) (Details) | 12 Months Ended
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Dec. 31, 2015 USD ($) plan $ / shares shares | Dec. 31, 2014 $ / shares shares | Dec. 31, 2013 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Share-based Compensation, Executive Retirements | $ | $ 10,400,000 |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights | retiring executive officers who are at least 57 years of age at the time of retirement, have been employed by the Company for 10 years, and have not been terminated for "cause" as defined under the 2011 Plan. |  |
Shares available for grant/issuance | 2,487,881 |  |
Unrecognized compensation expense for all nonvested awards | $ | $ 16,800,000 |  |
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition | 1 year 9 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 | 2.35 |  |
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 | 147,908 | 133,823 | 175,498
Granted at target level | $ / shares | $ 55.49 | $ 47.21 | $ 29.67
Employee Stock Purchase Plan (ESPP) [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Shares available for grant/issuance | 4,100,000 |  |
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 | 61,757 | 76,751 | 84,675
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 | 41,458 |  |
Granted at target level | $ / shares | $ 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 | 1,500 | 4,200 | 5,300
Vesting period | 4 years |  |
Granted at target level | $ / shares | $ 51.53 | $ 48.69 | $ 29.56
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 | 1,386 | 1,584 | 25,538
Granted at target level | $ / shares | $ 54.14 | $ 47.34 | $ 29.56
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] |  |  |
Number of deferred compensation plans | plan | 2 |  |
Number of deferred stock units | 496,976 |  |
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 | 22,746 |  |
Granted at target level | $ / shares | $ 53.25 |  |

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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 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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