Consolidated Statements of Income - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue:
Total revenue		$ 3,554,075	$ 3,205,125	$ 3,211,522
Costs and expenses:
Selling, general and administrative		963,323	1,003,989	1,002,935
Research and development		38,384	51,258	58,523
Restructuring charges and asset impairments		20,712	69,606	25,899
Goodwill impairment		198,169	0	0
Interest expense, net		105,753	110,910	115,381
Other components of net pension and postretirement (income) cost		(1,708)	(4,225)	22,425
Other expense, net		8,151	24,306	7,964
Total costs and expenses		3,739,007	3,177,983	3,023,401
Total		(184,932)	27,142	188,121
Provision (benefit) for income taxes		6,727	(13,007)	6,416
(Loss) income from continuing operations		(191,659)	40,149	181,705
Income from discontinued operations, net of tax		10,115	154,460	60,106
Net (loss) income		$ (181,544)	$ 194,609	$ 241,811
Basic earnings per share attributable to common stockholders:
Continuing operations (in dollars per share)	[1]	$ (1.12)	$ 0.23	$ 0.97
Discontinued operations (in dollars per share)	[1]	0.06	0.88	0.32
Net income (in dollars per share)	[1]	(1.06)	1.10	1.29
Diluted earnings per share attributable to common stockholders:
Continuing operations (in dollars per share)	[1]	(1.12)	0.23	0.96
Discontinued operations (in dollars per share)	[1]	0.06	0.87	0.32
Net income (in dollars per share)	[1]	$ (1.06)	$ 1.10	$ 1.28
Business services
Revenue:
Total from contracts with customers		$ 2,191,306	$ 1,710,801	$ 1,566,470
Total revenue		2,191,306	1,710,801	1,566,470
Costs and expenses:
Cost of products and sales		1,904,078	1,389,569	1,233,105
Support services
Revenue:
Total from contracts with customers		473,292	506,187	552,472
Total revenue		473,292	506,187	552,472
Costs and expenses:
Cost of products and sales		149,988	162,300	178,495
Financing
Revenue:
Total from contracts with customers		0	0	0
Total revenue		341,034	368,090	394,557
Costs and expenses:
Cost of products and sales		48,162	44,648	44,376
Equipment sales
Revenue:
Total from contracts with customers		74,660	80,562	88,616
Total revenue		314,882	352,104	395,652
Costs and expenses:
Cost of equipment sales		236,716	244,210	236,160
Supplies
Revenue:
Total from contracts with customers		159,282	187,287	218,304
Total revenue		159,282	187,287	218,304
Costs and expenses:
Cost of products and sales		41,679	49,882	60,960
Rentals
Revenue:
Total from contracts with customers		0	0	0
Total revenue		74,279	80,656	84,067
Costs and expenses:
Cost of products and sales		$ 25,600	$ 31,530	$ 37,178

[1] The sum of the earnings per share amounts may not equal the totals due to rounding.