Depreciation and Amortization (Tables)

12 Months Ended

Dec. 31, 2018

Depreciation And Amortization [Abstract]

Depreciation and Amortization Expense Excluded from Operating Expenses in its Statements of Income

The amounts of depreciation and amortization expense excluded from the following operating expenses in its Statements of Income are:

	Year Ended December 31,
	2018		2017		2016
Direct expenses	$	212,585	$	196,107	$	191,169
General and administrative expenses		4,134		4,151		3,650
Corporate expenses		8,542		10,846		10,139
	$	225,261	$	211,104	$	204,958