How do companies account for and disclose their leases under the new accounting standard ASC 842 and IFRS 16, and what are the key differences between the previous accounting treatment of leases and the current treatment? Additionally, how do these changes in lease accounting impact the financial statements of a company, specifically the balance sheet and income statement, and what are the potential challenges and considerations for companies in adopting and implementing the new standard? Furthermore, how do these changes in lease accounting affect the decision-making process for companies when entering into leases, such as the evaluation of lease vs buy options, and how do they impact the analysis of a company's financial performance and position by investors and other stakeholders