CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net income	$ 33,285	$ 32,773	$ 42,824
Adjustments to reconcile net income to cash provided by operating activities:
Deferred income tax provision, net	12,243	2,007	2,380
Provision for bad debt	1,031	976	1,553
Depreciation and amortization	8,508	8,796	9,849
Stock-based compensation expense	7,600	6,705	5,819
Defined benefit pension plans expense	937	1,733	1,846
Loss on deferred compensation plan investments, net	510	597	77
Gain on sale of Global's assets	(3,148)	0	0
Contingent consideration liability remeasurement	565	(42)	321
Other	888	321	308
(Increase) decrease in operating assets
Trade receivables, net	(20,535)	(8,403)	4,223
Income tax refund receivable	(6,944)	354	2,785
Prepaid expenses and other current assets	(1,471)	(1,631)	1,110
Other assets, net	(556)	(495)	(298)
(Decrease) increase in operating liabilities
Accounts payable and other current liabilities	(1,537)	(1,920)	1,788
Accrued payroll costs	1,954	(1,320)	(5,503)
Income taxes payable	(221)	(489)	(1,657)
Other long-term liabilities	(3,770)	(139)	3,306
Cash provided by operating activities	29,339	39,823	70,731
Cash flows from investing activities:
Capital expenditures	(5,846)	(12,420)	(8,328)
Proceeds from sale of Global's assets	1,000	0	0
Proceeds from the disposition of assets held within the Rabbi Trust	0	0	445
Purchase of assets held within the Rabbi Trust	0	0	(481)
Cash used in investing activities	(4,846)	(12,420)	(8,364)
Cash flows from financing activities:
Proceeds from credit facility	1,038,593	937,083	604,668
Payments on credit facility	(1,033,617)	(906,008)	(617,529)
Proceeds from other financing arrangements	0	1,783	2,914
Payments on other financing arrangements	(2,148)	(1,830)	(1,274)
Payments of loan financing fees	(1,730)	(158)	0
Proceeds from exercise of stock options, net of shares tendered in payment of exercise	72	172	381
Repurchases of common stock	(14,622)	(46,013)	(38,471)
Cash dividend	(12,144)	(12,447)	(12,545)
Other	0	0	(252)
Cash used in financing activities	(25,596)	(27,418)	(62,108)
Change in cash and cash equivalents	(1,103)	(15)	259
Cash and cash equivalents at beginning of period	1,482	1,497	1,238
Cash and cash equivalents at end of period	$ 379	$ 1,482	$ 1,497