Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash flows from operating activities:
Net income	$ 9,156	$ 72
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	3,489	2,410
Bad debt provision	18,470	37,137
Stock-based compensation expense	1,838	1,569
Amortization of premium on marketable securities	382	339
Unrealized gain on deferred compensation fund investments	(3,445)	(300)
Changes in operating assets and liabilities:
Accounts and notes receivable	(25,986)	(16,769)
Inventories and supplies	300	119
Prepaid expenses and other assets	(323)	(3,483)
Deferred compensation funding	744	(259)
Accounts payable and other accrued expenses	(5,322)	(5,478)
Accrued payroll, accrued and withheld payroll taxes	18,465	18,546
Income taxes payable	(5,730)	(14,439)
Accrued insurance claims	2,622	3,443
Deferred compensation liability	2,917	1,024
Net cash provided by operating activities	17,577	23,931
Cash flows from investing activities:
Disposals of fixed assets	64	63
Additions to property and equipment	(1,336)	(1,335)
Purchases of marketable securities	(4,277)	(5,397)
Sales of marketable securities	3,539	2,467
Net cash used in investing activities	(2,010)	(4,202)
Cash flows from financing activities:
Dividends paid	(14,588)	(14,149)
Reissuance of treasury stock pursuant to Dividend Reinvestment Plan	24	24
Proceeds from the exercise of stock options	1,913	5,005
Net repayments from short-term borrowings	0	(9,382)
Payments of statutory withholding on net issuance of restricted stock units	(579)	(295)
Net cash used in financing activities	(13,230)	(18,797)
Net change in cash and cash equivalents	2,337	932
Cash and cash equivalents at beginning of the period	26,025	9,557
Cash and cash equivalents at end of the period	$ 28,362	$ 10,489