Long-Term Debt (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Debt Instruments [Abstract]
Credit facility	$ 42,000	$ 0
Deferred financing costs	(6,407)	(9,678)
Long-term debt	500,937	455,666
Less current portion	0	0
Long-term debt, less current portion	500,937	455,666
Loss on early extinguishment of debt	0	0	$ 8,073
Interest expense [Abstract]
Contractual coupon interest			12,185
Non-cash amortization of debt discount	0	0	13,161
Other Noncash Interest Expense (Income)			1,623
Total interest expense related to the debentures			26,969
Principal amount of repurchased debt			151,546
Committed and uncommitted short-term credit lines	1,000	1,000
Aggregate annual maturities of long-term debt [Abstract]
Interest paid	13,739	14,177	15,450
Revolving Credit Facility [Member]
Line of Credit Facility [Abstract]
Line of credit facility, maximum borrowing capacity	$ 750,000
Line of credit facility, expiration date	Jun. 05, 2024
Incremental revolving commitments	$ 300,000
Basis spread on variable rate	1.50%
Commitment fees	0.25%
Investments pro forma ratio	2.75
Restricted payments pro forma ratio	2.5
Restricted payments, annual limit	$ 100,000
Restricted payments ,total limit	300,000
Restricted payments ,rollover limit	25,000
Restricted payments, unused amount	100,000
Event of default - judgment limit	50,000
Available borrowing capacity	707,061	748,931
Letters of credit outstanding	939	1,069
Convertible Senior Notes, Due 2025 [Member]
Debt Instruments [Abstract]
Convertible debt	$ 465,344	465,344
Issuance date	Jun. 12, 2018
Maturity date	Jun. 15, 2025
Cash coupon rate	2.25%
Nonconvertible debt borrowing rate at issuance	5.50%
Effective conversion rate	32.0478
Effective conversion price (in dollars per share)	$ 31.2
130% of the conversion price (in dollars per share)	$ 40.56
Debt instrument percentage of conversion price	130.00%
Debt instrument, percentage of sale price of common stock	98.00%
Maximum threshold of quarterly cash dividends per share of common stock for not adjusting conversion rate of convertible notes (in dollars per share)	$ 0.085
Purchase price of extinguished debt		128,328
Allocated liability component of repurchased debt		118,587
Allocated equity component of repurchased debt		9,741
Loss on early extinguishment of debt		4,600
Liability and equity components of convertible debentures [Abstract]
Principal amount of the convertible debt	$ 465,344
Carrying value of liability component		465,344
Interest expense [Abstract]
Contractual coupon interest	10,470	10,470	12,097
Non-cash amortization of debt discount	0	0	13,118
Other Noncash Interest Expense (Income)	1,733	1,733	1,623
Total interest expense related to the debentures	$ 12,203	12,203	26,838
Principal amount of repurchased debt		134,656
Net carrying value of repurchased debt		115,978
Convertible Senior Debentures, Due 2040 [Member]
Debt Instruments [Abstract]
Allocated liability component of repurchased debt		$ 300
Convertible Senior Debentures, Due 2041 [Member]
Debt Instruments [Abstract]
Purchase price of extinguished debt			23,355
Allocated liability component of repurchased debt			10,075
Allocated equity component of repurchased debt			13,280
Loss on early extinguishment of debt			3,473
Interest expense [Abstract]
Principal amount of repurchased debt			16,890
Net carrying value of repurchased debt			6,715
Convertible Senior Debentures [Member]
Interest expense [Abstract]
Contractual coupon interest			88
Non-cash amortization of debt discount			43
Other Noncash Interest Expense (Income)			0
Total interest expense related to the debentures			$ 131