| Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block] |
| | | | | | | | | | | | | | | | | | | | | | | | | March 31, 2024 | | December 31, 2023 | | (In thousands) | Carrying Value | | Estimated Fair Value | | Carrying Value | | Estimated Fair Value | 3.85% Senior notes due 2025 | 90,000 | | | 88,655 | | | 90,000 | | | 88,243 | | 4.24% Senior notes due 2026 | 200,000 | | | 194,444 | | | 200,000 | | | 195,556 | | 4.05% Senior notes due 2028 | 67,500 | | | 64,289 | | | 67,500 | | | 64,801 | | 4.11% Senior notes due 2028 | 90,000 | | | 85,213 | | | 90,000 | | | 85,999 | | 3.10% Senior notes due 2030 | 150,000 | | | 130,433 | | | 150,000 | | | 131,942 | | 3.20% Senior notes due 2032 | 150,000 | | | 125,714 | | | 150,000 | | | 127,649 | | 4.49% Senior notes due 2032 | 200,000 | | | 184,346 | | | 200,000 | | | 187,584 | | 4.64% Senior notes due 2034 | 100,000 | | | 91,533 | | | 100,000 | | | 92,961 | | | Total debt | 1,047,500 | | | 964,627 | | | 1,047,500 | | | 974,735 | | | Debt issuance costs, net | (1,487) | | | (1,487) | | | (1,541) | | | (1,541) | | | Unamortized interest rate swap proceeds | 3,996 | | | 3,996 | | | 4,403 | | | 4,403 | | | Total debt, net | $ | 1,050,009 | | | $ | 967,136 | | | 1,050,362 | | | 977,597 | |
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