UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended				6 Months Ended		12 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Cash flows from operating activities:
Net income	$ 9,885	$ 9,106	$ 74,859	$ 26,855	$ 18,991	$ 101,714
Adjustments to reconcile net income to cash provided by operating activities:
Deferred income tax provision, net					(3,741)	1,735
Provision for credit losses					2,835	797
Depreciation and amortization					2,773	3,623
Stock-based compensation expense					5,799	5,050
Defined benefit pension plan expense					422	431
Loss (gain) on deferred compensation plan investments, net					424	(10)
Loss on disposal or impairment of assets					1,092	970
Noncash lease expense					3,086	3,187
Loss on equity method investment					1,134	0
Gain on sale of discontinued operations					0	(80,004)
Other					176	636
(Increase) decrease in operating assets
Trade receivables, net					(27,585)	(12,829)
Other assets					(2,510)	(3,269)
Increase (decrease) in operating liabilities
Accrued payroll costs					10,588	1,298
Other liabilities					25,482	(999)
Cash provided by operating activities					38,966	22,330
Cash flows from investing activities:
Capital expenditures					(3,793)	(4,184)
Equity method investment					(2,500)	(7,500)
Proceeds from the sale of assets held within the Rabbi Trust					3,548	0
Net proceeds from the sale of assets held for sale					0	122,696
Cash (used in) provided by investing activities					(2,745)	111,012
Cash flows from financing activities:
Proceeds from credit facility					35,000	80,100
Payments on credit facility					0	(86,900)
Repurchases of common stock					(29,593)	(51,546)
Cash dividends					(8,455)	(8,684)
Payments on other financing arrangements					(633)	(875)
Other					0	(502)
Cash used in financing activities					(3,681)	(68,407)
Change in cash and cash equivalents					32,540	64,935
Cash and cash equivalents, beginning of period		19,831		112	19,831	112	$ 112
Cash and cash equivalents, end of period	52,371		65,047		52,371	65,047	$ 19,831
Cash Paid During the Period For:
Income taxes					1,043	8,447
Operating lease liabilities					3,949	4,025
Interest, net					1,281	788
Non-Cash Investing and Financing Transactions:
ROU assets obtained from operating leases					2,971	1,355
Employee stock purchase plan	$ 134	$ 142	$ 143	$ 140	276	283
Contingent contribution for equity method investment					0	1,500
Unsettled repurchases of common stock					$ 0	$ 1,183