Statement of Income (Statement) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenue from Contract with Customer, Excluding Assessed Tax	$ 263,825,000	$ 143,544,000	$ 717,462,000	$ 460,628,000
Revenues	265,315,000	144,501,000	721,281,000	467,183,000
Labor and Related Expense	185,904,000	103,893,000	513,321,000	329,640,000
General and Administrative Expense	29,155,000	28,899,000	83,876,000	91,122,000
Asset Impairment Charges	0	0	0	32,970,000
Operating Expenses	231,973,000	182,734,000	639,625,000	511,250,000
Operating Income (Loss)	33,342,000	(38,233,000)	81,656,000	(44,067,000)
Interest Income (Expense), Net	90,000	(180,000)	207,000	160,000
Other Nonoperating Income (Expense)	145,000	1,819,000	6,260,000	460,000
Nonoperating Income (Expense)	235,000	1,639,000	6,467,000	620,000
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	33,577,000	(36,594,000)	88,123,000	(43,447,000)
Income Tax Expense (Benefit)	9,079,000	(10,416,000)	28,028,000	(202,000)
Net Income (Loss) Attributable to Parent	24,498,000	(26,178,000)	60,095,000	(43,245,000)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	(661,000)	849,000	(1,349,000)	(1,381,000)
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax, Portion Attributable to Parent	0	1,000	0	(14,000)
Other Comprehensive Income (Loss), Net of Tax	(661,000)	850,000	(1,349,000)	(1,395,000)
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	$ 23,837,000	$ (25,328,000)	$ 58,746,000	$ (44,640,000)
Weighted Average Number of Shares Outstanding, Basic	19,569,000	19,351,000	19,489,000	19,281,000
Weighted Average Number of Shares Outstanding, Diluted	20,240,000	19,351,000	20,259,000	19,281,000
Earnings Per Share, Basic	$ 1.25	$ (1.35)	$ 3.08	$ (2.24)
Earnings Per Share, Diluted	1.21	(1.35)	2.97	(2.24)
Common Stock, Dividends, Per Share, Declared	$ 0.15	$ 0.15	$ 0.45	$ 0.45
Restructuring Charges	$ (3,262,000)	$ 48,115,000	$ 3,792,000	$ 48,115,000
Reimbursements
Revenue from Contract with Customer, Excluding Assessed Tax	1,490,000	957,000	3,819,000	6,555,000
Cost of Goods and Services Sold	1,490,000	957,000	3,819,000	6,555,000
Cost of Services
Cost of Goods and Services Sold	$ 18,686,000	$ 870,000	$ 34,817,000	$ 2,848,000