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Percentage of earnings deferred into company stock units company match.

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Percentage of earnings deferred into company stock units deferred in mutual funds.

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Amount of increase (decrease) in additional paid in capital (APIC) resulting from a tax benefit (deficiency) associated with an share-based compensation plan other than an employee stock ownership plan (ESOP).

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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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Aggregate carrying value as of the balance sheet date of the liabilities for all deferred compensation arrangements. Represents currently earned compensation under compensation arrangements that is not actually paid until a later date.

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

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Aggregate proceeds received by the entity during the annual period from exercises of stock or unit options and conversion of similar instruments granted under equity-based payment arrangements.

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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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Disclosure of the aggregate tax benefit realized from the exercise of stock options and the conversion of similar instruments during the annual period.

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Sum of the carrying amounts as of the balance sheet date of all investments.

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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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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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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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

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Percentage of vesting of share-based compensation awards.

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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 ($) $ in Thousands		12 Months Ended
	Jun. 05, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized to grant		6,000,000
Stock-based compensation		$ 186,303	$ 165,641	$ 94,006
Tax benefit (provision) related to stock-based compensation recognized in shareholders' equity		(4,904)	14,741	19,858
Issuance of common stock for acquisitions		$ 12,813	79,747	19,243
Options granted during the period		0
Total intrinsic value of options exercised				1,600
Cash proceeds from the exercise of stock options				300
Tax benefits realized from the exercise of stock options		$ 100	600	500
Investments, at fair value		133,563	181,017
Deferred compensation liability		8,600	12,400
Contributions to the Profit Sharing Plan		$ 6,500	7,700	4,900
Mutual Funds [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of earnings deferred into mutual funds		2.00%
Investments, at fair value		$ 11,300	15,500
Incentive Stock Award Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation		190,100	142,100	111,600
Tax benefit (provision) related to stock-based compensation recognized in shareholders' equity		(4,900)	$ 14,700	$ 19,900
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
Issuance of common stock for acquisitions	$ 23,800
Total number of stock units outstanding		21,800,000
Unvested stock units outstanding		16,276,000	12,274,000
Unrecognized compensation expense related to non-vested options		$ 379,100
Weighted-average period, compensation cost expected to recognized, in years		3 years 2 months 12 days
Fair value of stock units vested		$ 134,100
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 units outstanding		500,000
Unvested stock units outstanding		500,000
SWAP Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Elective deferrals vested percentage		100.00%
Percentage of earnings deferred into company stock units		4.00%
Percentage of earnings deferred into company stock units, Company match		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] \| Performance-based Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Potential shares vesting percentage		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		8 years
Maximum [Member] \| Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards vesting period in years		8 years
Maximum [Member] \| Performance-based Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Potential shares vesting percentage		200.00%
Maximum [Member] \| SWAP Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards vesting period in years		8 years