Fair Value Measurements and Derivative Instruments (Recurring Basis) (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities	$ 274,106	$ 325,794
Fair Value, Recurring
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Money market funds	426,748	508,019
Equity securities	29,356	26,583
Mortgage-backed / asset-backed securities	172,018	220,678
Total assets	752,602	885,413
Total liabilities	(304)	(4,123)
Fair Value, Recurring | Interest rate swaps
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative asset	3,103
Derivative liability		(2,163)
Fair Value, Recurring | Foreign exchange contracts
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative asset	2,474	3,776
Derivative liability	(304)	(1,960)
Commingled fixed income securities
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities	1,692	1,722
Commingled fixed income securities | Fair Value, Recurring
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities	18,507	21,391
Government and related securities
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities	35,229	31,961
Government and related securities | Fair Value, Recurring
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities	35,229	33,533
Corporate debt securities
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities	65,167	71,433
Corporate debt securities | Fair Value, Recurring
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities	65,167	71,433
Level 1 | Fair Value, Recurring
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Money market funds	88,705	73,228
Equity securities	0	0
Mortgage-backed / asset-backed securities	0	0
Total assets	100,187	91,726
Total liabilities	0	0
Level 1 | Fair Value, Recurring | Interest rate swaps
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative asset	0
Derivative liability		0
Level 1 | Fair Value, Recurring | Foreign exchange contracts
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative asset	0	0
Derivative liability	0	0
Level 1 | Commingled fixed income securities | Fair Value, Recurring
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities	1,692	1,722
Level 1 | Government and related securities | Fair Value, Recurring
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities	9,790	16,776
Level 1 | Corporate debt securities | Fair Value, Recurring
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities	0	0
Level 2 | Fair Value, Recurring
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Money market funds	338,043	434,791
Equity securities	29,356	26,583
Mortgage-backed / asset-backed securities	172,018	220,678
Total assets	652,415	793,687
Total liabilities	(304)	(4,123)
Level 2 | Fair Value, Recurring | Interest rate swaps
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative asset	3,103
Derivative liability		(2,163)
Level 2 | Fair Value, Recurring | Foreign exchange contracts
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative asset	2,474	3,776
Derivative liability	(304)	(1,960)
Level 2 | Commingled fixed income securities | Fair Value, Recurring
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities	16,815	19,669
Level 2 | Government and related securities | Fair Value, Recurring
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities	25,439	16,757
Level 2 | Corporate debt securities | Fair Value, Recurring
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities	65,167	71,433
Level 3 | Fair Value, Recurring
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Money market funds	0	0
Equity securities	0	0
Mortgage-backed / asset-backed securities	0	0
Total assets	0	0
Total liabilities	0	0
Level 3 | Fair Value, Recurring | Interest rate swaps
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative asset	0
Derivative liability		0
Level 3 | Fair Value, Recurring | Foreign exchange contracts
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative asset	0	0
Derivative liability	0	0
Level 3 | Commingled fixed income securities | Fair Value, Recurring
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities	0	0
Level 3 | Government and related securities | Fair Value, Recurring
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities	0	0
Level 3 | Corporate debt securities | Fair Value, Recurring
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities	$ 0	$ 0