Fair Value of Financial Instruments - Other Investments - Other Equity Method Investments - Narrative (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity method investments, net investment	$ 288,000,000		$ 288,000,000			$ 267,000,000
Equity method investments, equity in earnings (losses)	6,587,000	$ 7,525,000	13,364,000	$ 14,871,000
Telecommunications Equity Method Investees
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity method investments, net investment	20,000,000		20,000,000			20,000,000
Equity method investments, equity contributions	600,000	0	1,100,000	2,000,000
Equity method investments, equity in earnings (losses)	(500,000)	(1,000,000)	(900,000)	(1,000,000)
Payments for advance to affiliate	0		0	200,000
Telecommunications Equity Method Investees | Subcontracting Arrangements
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Expenses, related party	1,600,000	2,400,000	2,500,000	4,100,000
Payables, related party	100,000		100,000			300,000
Telecommunications Equity Method Investees | Employee Leasing and Advanced Receivable Arrangement
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Receivables, related party	600,000		600,000			900,000
FM Tech
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity method investments, net investment	$ 18,000,000		$ 18,000,000			17,000,000
Equity method investments, ownership percentage	50.00%		50.00%
Certain Entities, Each Accounted for Using Equity Method Investments
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity method investments, net investment		4,000,000		4,000,000		4,000,000
Equity method investments, equity in earnings (losses)	$ 200,000		$ 300,000
Expenses, related party	$ 1,400,000		$ 5,000,000
Equity method investments, ownership percentage	49.00%		49.00%
Payables, related party	$ 100,000		$ 100,000
Line of credit, amount drawn	4,500,000		4,500,000			8,500,000
Certain Entities, Each Accounted for Using Equity Method Investments | Other Current Assets
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Line of credit, amount drawn	500,000		500,000			$ 400,000
Confluence
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity method investments, equity contributions	200,000	600,000	1,900,000	1,000,000
Equity method investments, equity in earnings (losses)	$ (100,000)	$ 300,000	$ (300,000)	$ 300,000
Equity method investments, ownership percentage					75.00%
Financing commitments (up to)							$ 2,500,000