The carrying value of our notes payable, capital leases and long-term debt as of June 30, 2018 and December 31, 2017 is listed in the following table, and is adjusted for the fair value of interest rate swaps, unamortized discounts, deferred issuance costs and the unamortized portion of adjustments to fair value recorded in purchase accounting. Original issue discounts and adjustments to fair value recorded in purchase accounting are amortized to interest expense over the term of the applicable instrument using the effective interest method. | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | June 30, 2018 | | December 31, 2017 | Maturity | | Interest Rate | | Principal | | Adjustments | | Carrying Value | | Principal | | Adjustments | | Carrying Value | Credit facilities: | | | | | | | | | | | | | | | Uncommitted Credit Facility | | Variable | | $ | 44.7 |
| | $ | — |
| | $ | 44.7 |
| | $ | — |
| | $ | — |
| | $ | — |
| June 2019 | | Variable | | — |
| | — |
| | — |
| | 130.0 |
| | — |
| | 130.0 |
| May 2021 | | Variable | | — |
| | — |
| | — |
| | — |
| | — |
| | — |
| June 2023 | | Variable | | 80.0 |
| | — |
| | 80.0 |
| | — |
| | — |
| | — |
| Senior notes: | | | | | | | | | | | | | | | May 2018 | | 3.800 | | — |
| | — |
| | — |
| | 700.0 |
| | (0.3 | ) | | 699.7 |
| September 2019 | | 5.500 | | 650.0 |
| | (1.5 | ) | | 648.5 |
| | 650.0 |
| | (2.1 | ) | | 647.9 |
| March 2020 | | 5.000 | | 850.0 |
| | (1.3 | ) | | 848.7 |
| | 850.0 |
| | (1.8 | ) | | 848.2 |
| November 2021 | | 5.250 | | 600.0 |
| | (1.4 | ) | | 598.6 |
| | 600.0 |
| | (1.5 | ) | | 598.5 |
| June 2022 | | 3.550 | | 850.0 |
| | (4.1 | ) | | 845.9 |
| | 850.0 |
| | (4.6 | ) | | 845.4 |
| May 2023 | | 4.750 | | 550.0 |
| | (10.0 | ) | | 540.0 |
| | 550.0 |
| | (1.0 | ) | | 549.0 |
| March 2025 | | 3.200 | | 500.0 |
| | (4.5 | ) | | 495.5 |
| | 500.0 |
| | (4.8 | ) | | 495.2 |
| June 2026 | | 2.900 | | 500.0 |
| | (4.7 | ) | | 495.3 |
| | 500.0 |
| | (5.0 | ) | | 495.0 |
| November 2027 | | 3.375 | | 650.0 |
| | (6.4 | ) | | 643.6 |
| | 650.0 |
| | (7.0 | ) | | 643.0 |
| May 2028 | | 3.950 | | 800.0 |
| | (18.1 | ) | | 781.9 |
| | — |
| | — |
| | — |
| March 2035 | | 6.086 | | 181.9 |
| | (14.7 | ) | | 167.2 |
| | 181.9 |
| | (14.9 | ) | | 167.0 |
| March 2040 | | 6.200 | | 399.9 |
| | (3.9 | ) | | 396.0 |
| | 399.9 |
| | (3.9 | ) | | 396.0 |
| May 2041 | | 5.700 | | 385.7 |
| | (5.4 | ) | | 380.3 |
| | 385.7 |
| | (5.5 | ) | | 380.2 |
| Debentures: | | | | | | | | | | | | | | | May 2021 | | 9.250 | | 35.3 |
| | (0.8 | ) | | 34.5 |
| | 35.3 |
| | (1.0 | ) | | 34.3 |
| September 2035 | | 7.400 | | 148.1 |
| | (34.1 | ) | | 114.0 |
| | 148.1 |
| | (34.5 | ) | | 113.6 |
| Tax-exempt: | | | | | | | | | | | | | | | 2019 - 2044 | | 1.450 - 5.250 | | 1,042.4 |
| | (5.8 | ) | | 1,036.6 |
| | 1,042.4 |
| | (6.4 | ) | | 1,036.0 |
| Capital leases: | | | | | | | | | | | | | | | 2018 - 2046 | | 3.273 - 12.203 | | 106.4 |
| | — |
| | 106.4 |
| | 108.4 |
| | — |
| | 108.4 |
| Total Debt | | | | $ | 8,374.4 |
| | $ | (116.7 | ) | | 8,257.7 |
| | $ | 8,281.7 |
| | $ | (94.3 | ) | | 8,187.4 |
| Less: current portion | | | | | | | | (41.9 | ) | | | | | | (706.7 | ) | Long-term portion | | | | | | | | $ | 8,215.8 |
| | | | | | $ | 7,480.7 |
|
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