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Percentage of earnings deferred into company stock units additional elective deferral.

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Percentage of earnings deferred into company stock units company match.

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Sharebased compensation arrangement by share based payment award award shares potentially converted range percentage.

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Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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Amount of discretionary contributions made by an employer to a defined contribution plan.

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Unrecognized cost of unvested share-based compensation awards.

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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.

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Additional share-based compensation cost recognized as a result of an occurrence of an event that accelerates its recognition.

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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.

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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.

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Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

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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.

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Number of equity instruments other than options outstanding, including both vested and non-vested instruments.

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Number of additional shares authorized for issuance under an established share-based compensation plan.

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Net number of share options (or share units) granted during the period.

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Number of options outstanding, including both vested and non-vested options.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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An excess of the fair value of the modified award over the fair value of the award immediately before the modification.

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Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Value of stock issued pursuant to acquisitions during the period.

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Employee Incentive, Deferred Compensation, And Retirement Plans (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized to grant										6,700,000
Stock-based compensation										$ 140,461	$ 186,303	$ 165,641
Provision for income tax expense (benefit)		$ 1,168	$ 41,603	$ 30,387	$ 13,507	$ 28,014	$ 10,168	$ 6,022	$ 16,858	86,665	61,062	49,231
Restricted stock units, charges at the date of modification										$ 55,900
Vesting of outstanding debenture awards	$ 51,400
Options granted during the period										0
Options outstanding during the period	11,934	11,934								11,934
Weighted average exercise price	$ 29.33	$ 29.33								$ 29.33
Contributions to the Profit Sharing Plan										$ 7,100	6,500	7,700
Incentive Stock Award Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation										246,700	190,100	142,100
Incentive Stock Award Plans [Member] \| ASU No. 2016-09 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Provision for income tax expense (benefit)										$ (64,700)	4,900	$ (14,700)
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units, charges at the date of modification											58,600
Common stock issued for acquisitions											$ 23,800
Restricted Stock Units and Restricted Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total number of stock awards outstanding	16,500,000	16,500,000								16,500,000
Unvested stock awards outstanding	12,279,000	12,279,000				16,276,000				12,279,000	16,276,000
Unrecognized compensation expense related to non-vested options	$ 251,300	$ 251,300								$ 251,300
Weighted-average period, compensation cost expected to recognized, in years										3 years 1 month 6 days
Fair value of stock awards vested										$ 185,800
Performance-based Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards vesting period in years										5 years
Award performance period										4 years
Total number of stock awards outstanding	600,000	600,000								600,000
Unvested stock awards outstanding	600,000	600,000								600,000
SWAP Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Elective deferrals vested percentage	100.00%	100.00%								100.00%
Percentage of earnings deferred into company stock units	5.00%	5.00%								5.00%
Percentage of earnings deferred into company stock units, Company match	25.00%	25.00%								25.00%
Percentage of earnings deferred into company stock units, Additional elective deferral										1.00%
Minimum [Member] \| Deferred Compensation Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards vesting period in years										1 year
Minimum [Member] \| Incentive Stock Award Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards vesting period in years										1 year
Minimum [Member] \| Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards vesting period in years										1 year
Minimum [Member] \| Restricted Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards vesting period in years										1 year
Minimum [Member] \| Performance-based Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Potential percentage of converted shares										0.00%
Minimum [Member] \| SWAP Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards vesting period in years										1 year
Maximum [Member] \| Deferred Compensation Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards vesting period in years										8 years
Maximum [Member] \| Incentive Stock Award Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards vesting period in years										10 years
Maximum [Member] \| Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards vesting period in years										10 years
Maximum [Member] \| Restricted Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards vesting period in years										5 years
Maximum [Member] \| Performance-based Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Potential percentage of converted shares										200.00%
Maximum [Member] \| SWAP Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards vesting period in years										10 years