Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2021

Accounting Policies [Abstract]

Employee Deferred Compensation Plans

The following table presents the Company’s income from investments held in employee deferred compensation trusts (in thousands):

	Year Ended December 31,
	2021		2020		2019
Dividend income	$	23,719	$	8,322	$	10,425
Realized and unrealized gains	37,359		66,866		44,492
Income from investments held in employee deferred compensation trusts	$	61,078	$	75,188	$	54,917

Schedule of Allocation of Plan Assets

The following table sets forth the composition of the underlying assets which comprise the Company’s deferred

compensation trust assets (in thousands):

	Fair Value Measurements Using
	Balance at December 31, 2021		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)	Significant Unobservable Inputs (Level 3)
Assets
Money market funds	$	66,700	$	66,700	—	—
Mutual funds - bond	30,750		30,750		—	—
Mutual funds - stock	303,277		303,277		—	—
Mutual funds - blend	94,264		94,264		—	—
	$	494,991	$	494,991	—	—
	Fair Value Measurements Using
	Balance at December 31, 2020		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)	Significant Unobservable Inputs (Level 3)
Assets
Money market funds	$	69,681	$	69,681	—	—
Mutual funds - bond	27,282		27,282		—	—
Mutual funds - stock	234,667		234,667		—	—
Mutual funds - blend	75,004		75,004		—	—
	$	406,634	$	406,634	—	—

Accounts Receivable, Allowance for Credit Loss

The following table sets forth the activity in the allowance for credit losses from January 1, 2020, through December 31, 2021 (in thousands):

	Allowance for Credit Losses
Balance as of January 1, 2020	$	23,443
Charges to expense	4,200
Deductions	(7,906)
Other, including translation adjustments	(120)
Balance as of December 31, 2020	$	19,617
Charges to expense	9,464
Deductions	(6,827)
Other, including translation adjustments	(724)
Balance as of December 31, 2021	$	21,530

Depreciation Expense Computed Using Straight-Line Method over Useful Lives

Depreciation is computed using the straight-line method over the following useful lives:

Computer hardware	2 to 3 years
Computer software	2 to 5 years
Furniture and equipment	3 to 5 years
Leasehold improvements	Term of lease

Property and equipment consisted of the following (in thousands):

	December 31,
	2021		2020
Computer hardware	$	157,408	$	159,180
Computer software	246,013		250,585
Furniture and equipment	93,144		91,112
Leasehold improvements	165,153		164,807
Property and equipment, cost	661,718		665,684
Accumulated depreciation	(568,315)		(555,867)
Property and equipment, net	$	93,403	$	109,817