Other Financial Statement Data The following provides additional information concerning selected balance sheet accounts: | | | | | | | | | | | | | March 31, 2021 | | December 31, 2020 | | Other current assets | | | | Income and other taxes receivable | $ | 165.5 | | | $ | 181.4 | | Prepaid expenses | 89.4 | | | 80.4 | | Other | 68.1 | | | 65.1 | | | $ | 323.0 | | | $ | 326.9 | | | | | | Other assets | | | | Restricted cash | $ | 4.3 | | | $ | 12.3 | | MRO inventory | 135.2 | | | 137.7 | | Marketable securities held in trust | 729.9 | | | 734.3 | | Operating lease right-of-use assets | 154.4 | | | 173.1 | | Indemnification asset | 21.0 | | | 23.0 | | Long-term receivable | 46.8 | | | 52.6 | | Other | 255.2 | | | 255.8 | | | $ | 1,346.8 | | | $ | 1,388.8 | | | | | | Accrued liabilities | | | | | | | | | | | | Payroll and employee benefits | $ | 130.7 | | | $ | 195.5 | | Asset retirement obligations | 188.7 | | | 190.2 | | Receivable factoring liability | 86.6 | | | — | | Customer prepayments (a) | 352.8 | | | 287.6 | | Accrued income and other taxes | 68.6 | | | 83.1 | | Operating lease obligation | 61.4 | | | 64.0 | | Other | 392.6 | | | 412.7 | | | $ | 1,281.4 | | | $ | 1,233.1 | | | | | | Other noncurrent liabilities | | | | Asset retirement obligations | $ | 1,182.2 | | | $ | 1,203.7 | | Operating lease obligation | 96.3 | | | 109.6 | | Accrued pension and postretirement benefits | 149.7 | | | 158.5 | | Unrecognized tax benefits | 47.6 | | | 46.4 | | Other | 231.4 | | | 235.3 | | | $ | 1,707.2 | | | $ | 1,753.5 | |
______________________________ (a) The timing of recognition of revenue related to our performance obligations may be different than the timing of collection of cash related to those performance obligations. Specifically, we collect prepayments from certain customers in Brazil. In addition, cash collection from Canpotex may occur prior to delivery of product to the end customer. We generally satisfy our contractual liabilities within one quarter of incurring the liability.
|