NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS – (Continued)
Maturities of Debt Instruments
The following table sets forth maturities of the Company's debt, including mortgage and loans payable, and senior notes, gross of debt issuance costs, debt discounts and debt premiums, as of March 31, 2019 (in thousands):
2019 (9 months remaining)
Fair Value of Debt Instruments
The following table sets forth the estimated fair values of the Company's mortgage and loans payable and senior notes, including current maturities, as of (in thousands):
Mortgage and loans payable
The fair values of the mortgage and loans payable and 5.000% Infomart Senior Notes, which were not publicly traded, were estimated by considering the Company's credit rating, current rates available to the Company for debt of the same remaining maturities and terms of the debt (Level 2). The fair value of the senior notes, which were traded in the public debt market, was based on quoted market prices (Level 1).
The following table sets forth total interest costs incurred and total interest costs capitalized for the periods presented (in thousands):
Three Months Ended
Interest charges incurred
Total interest paid, net of capitalized interest, during the three months ended March 31, 2019 and 2018 was $136.3 million and $103.7 million, respectively.
Commitments and Contingencies
As a result of the Company's various IBX data center expansion projects, as of March 31, 2019, the Company was contractually committed for approximately $0.8 billion of unaccrued capital expenditures, primarily for IBX infrastructure equipment not yet delivered and labor not yet provided, in connection with the work necessary to open these IBX data centers and make them available to customers for installation. The Company also had numerous other, non-capital purchase commitments in place as of March 31, 2019, such as commitments to purchase power in select locations through the remainder of 2019 and thereafter, and other open purchase orders for goods or services to be delivered or provided during the remainder of 2019 and thereafter. Such other miscellaneous purchase commitments totaled approximately $0.9 billion as of March 31, 2019. In addition, the Company entered