MARATHON OIL CORPORATION Notes to Consolidated Financial Statements The following table summarizes financial instruments, excluding the derivative financial instruments reported above, by individual balance sheet line item at December 31, 2008 and 2007.
## Table 0 ##
(a) Includes restricted cash, cost method investments and miscellaneous long-term receivables or deposits.
(b) Excludes capital leases.
Our current assets and liabilities accounts contain financial instruments, the most significant of which are trade accounts receivables and payables.
We believe the carrying values of our current assets and liabilities approximate fair value, with the exception of the current portion of receivables from United States Steel and the current portion of our long-term debt which is reported above.
Our fair value assessment incorporates a variety of considerations, including (1) the short-term duration of the instruments (e. g. , less than 1 percent of our trade receivables and payables are outstanding for greater than 90 days), (2) our investment-grade credit rating, and (3) our historical incurrence of and expected future insignificance of bad debt expense, which includes an evaluation of counterparty credit risk.
The fair value of the receivables from United States Steel is measured using an income approach that discounts the future expected payments over the remaining term of the obligations.
Because this asset is not publicly-traded and not easily transferable, a hypothetical market based upon United States Steel’s borrowing rate curve is assumed and the majority of inputs to the calculation are Level 3.
The industrial revenue bonds are to be redeemed on or before the tenth anniversary of the USX Separation per the Financial Matters Agreement.
The majority of our restricted cash represent cash accounts that earn interest; therefore, the balance approximates fair value.
Other financial assets included in our other noncurrent assets line include cost method investments and miscellaneous long-term receivables or deposits.
Fair value for the cost method investments is measured using an income approach.
Estimated future cash flows, obtained from our internal forecasts or forecasts from the partially owned companies, are discounted to obtain the fair value.
Over 90 percent of our long-term debt instruments are publicly-traded.
A market approach, based upon quotes from major financial institutions is used to measure the fair value of such debt.
Because these quotes cannot be independently verified to the market they are considered Level 3 inputs.
The fair value of our debt that is not publicly-traded is measured using an income approach.
The future debt service payments are discounted using the rate at which we currently expect to borrow.
All inputs to this calculation are Level 3.
Long-term receivables and deposits are also measured using an income approach.
The expected timing of payments are scheduled and then discounted using a rate deemed appropriate.18.
Derivative Instruments Derivative instruments are recorded at fair value.
Derivative instruments on our consolidated balance sheet are reported on a net basis by brokerage firm, as permitted by master netting agreements.
For further information regarding the fair value measurement of derivative instruments see Note 17.
MARATHON OIL CORPORATION Notes to Consolidated Financial Statements 97 Components of net periodic benefit cost from continuing operations and other comprehensive (income) loss – The following summarizes the net periodic benefit costs and the amounts recognized as other comprehensive (income) loss for our defined benefit pension and other postretirement plans.
## Table 1 ##
(a) Related to workforce reductions, which reduced the future expected years of service for employees participating in the plans and the impact of discontinuing accruals for future benefits under the U. K.  pension plan effective December 31, 2015.
(b) Settlement losses are recorded when lump sum payments from a plan in a period exceed the plan’s total service and interest costs for the period.
Such settlements occurred in one or more of our U. S.  pension plans in all periods presented.
(c) Net periodic benefit cost reflects a calculated market-related value of plan assets which recognizes changes in fair value over three years.
(d) Activity in 2014 includes the impact of the sale of our Norway business in the fourth quarter of 2014.
The estimated net loss and prior service credit for our defined benefit pension plans that will be amortized from accumulated other comprehensive loss into net periodic benefit cost in 2016 are $12 million and $11 million.
The estimated prior service credit for our other defined benefit postretirement plans that will be amortized from accumulated other comprehensive loss into net periodic benefit cost in 2016 is $3 million.
Plan assumptions – The following summarizes the assumptions used to determine the benefit obligations at December 31, and net periodic benefit cost for the defined benefit pension and other postretirement plans for 2015, 2014 and 2013.
## Table 2 ##
(a) No future benefits will be incurred for the UK plan after December 31, 2015.
Therefore, rate of compensation increase is no longer applicable to this plan.
Borrowings reflect net proceeds received from the issuance of senior notes in June 2015.
See Liquidity and Capital Resources below for additional information.
In November 2015, we repaid our $1 billion 0.90% senior notes upon maturity.
In October 2015, we announced an adjustment to our quarterly dividend.
See Capital Requirements below for additional information.
Additions to property, plant and equipment are our most significant use of cash and cash equivalents.
The following table shows capital expenditures related to continuing operations by segment and reconciles to additions to property, plant and equipment as presented in the consolidated statements of cash flows for 2015, 2014 and 2013:
## Table 3 ##
(a) Reflects reimbursements earned from the governments of Canada and Alberta related to funds previously expended for Quest CCS capital equipment.
Quest CCS was successfully completed and commissioned in the fourth quarter of 2015.
During 2014, we acquired 29 million shares at a cost of $1 billion and in 2013 acquired 14 million shares at a cost of $500 million.
There were no share repurchases in 2015.
See Item 8.
Financial Statements and Supplementary Data – Note 23 to the consolidated financial statements for discussion of purchases of common stock.
Liquidity and Capital ResourcesOn June 10, 2015, we issued $2 billion aggregate principal amount of unsecured senior notes which consist of the following series:?
$600 million of 2.70% senior notes due June 1, 2020?
$900 million of 3.85% senior notes due June 1, 2025?
$500 million of 5.20% senior notes due June 1, 2045 Interest on each series of senior notes is payable semi-annually beginning December 1, 2015.
We used the aggregate net proceeds to repay our $1 billion 0.90% senior notes on November 2, 2015, and the remainder for general corporate purposes.
In May 2015, we amended our $2.5 billion Credit Facility to increase the facility size by $500 million to a total of $3.0 billion and extend the maturity date by an additional year such that the Credit Facility now matures in May 2020.
The amendment additionally provides us the ability to request two one-year extensions to the maturity date and an option to increase the commitment amount by up to an additional $500 million, subject to the consent of any increasing lenders.
The sub-facilities for swing-line loans and letters of credit remain unchanged allowing up to an aggregate amount of $100 million and $500 million, respectively.
Fees on the unused commitment of each lender, as well as the borrowing options under the Credit Facility, remain unchanged.
Our main sources of liquidity are cash and cash equivalents, internally generated cash flow from operations, capital market transactions, our committed revolving credit facility and sales of non-core assets.
Our working capital requirements are supported by these sources and we may issue either commercial paper backed by our $3.0 billion revolving credit facility or draw on our $3.0 billion revolving credit facility to meet short-term cash requirements or issue debt or equity securities through the shelf registration statement discussed below as part of our longer-term liquidity and capital management.
Because of the alternatives available to us as discussed above, we believe that our short-term and long-term liquidity is adequate to fund not only our current operations, but also our near-term and long-term funding requirements including our capital spending programs, dividend payments, defined benefit plan contributions, repayment of debt maturities and other amounts that may ultimately be paid in connection with contingencies.
General economic conditions, commodity prices, and financial, business and other factors could affect our operations and our ability to access the capital markets.
A downgrade in our credit ratings could negatively impact our cost of capital and our ability to access the capital markets, increase the interest rate and fees we pay on our unsecured revolving credit facility, restrict our access to the commercial paper market, or require us to post letters of credit or other forms of collateral for certain

<table><tr><td></td><td colspan="4">December 31,</td></tr><tr><td></td><td colspan="2">2008</td><td colspan="2">2007</td></tr><tr><td><i></i><i>(In millions)</i><i></i></td><td>FairValue</td><td>CarryingAmount</td><td>FairValue</td><td>CarryingAmount</td></tr><tr><td>Financial assets</td><td></td><td></td><td></td><td></td></tr><tr><td>Receivables from United States Steel, including current portion</td><td>$438</td><td>$492</td><td>$500</td><td>$507</td></tr><tr><td>Other noncurrent assets<sup>(a)</sup></td><td>286</td><td>113</td><td>1,140</td><td>899</td></tr><tr><td>Total financial assets</td><td>724</td><td>605</td><td>1,640</td><td>1,406</td></tr><tr><td>Financial liabilities</td><td></td><td></td><td></td><td></td></tr><tr><td>Long-term debt, including current portion<sup>(b)</sup></td><td>5,683</td><td>6,880</td><td>7,176</td><td>6,947</td></tr><tr><td>Total financial liabilities</td><td>$5,683</td><td>$6,880</td><td>$7,176</td><td>$6,947</td></tr></table>
<table><tr><td></td><td colspan="6">Pension Benefits Year Ended December 31,</td><td colspan="3">Other Benefits Year Ended December 31,</td></tr><tr><td></td><td colspan="2">2015</td><td colspan="2">2014</td><td colspan="2">2013</td><td>2015</td><td>2014</td><td>2013</td></tr><tr><td>(In millions)</td><td>U.S.</td><td>Int’l</td><td>U.S.</td><td>Int’l</td><td>U.S.</td><td>Int’l</td><td>U.S.</td><td>U.S.</td><td>U.S.</td></tr><tr><td>Components of net periodic benefit cost:</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Service cost</td><td>$29</td><td>$14</td><td>$31</td><td>$16</td><td>$33</td><td>$17</td><td>$3</td><td>$3</td><td>$4</td></tr><tr><td>Interest cost</td><td>25</td><td>25</td><td>35</td><td>27</td><td>40</td><td>23</td><td>11</td><td>13</td><td>12</td></tr><tr><td>Expected return on plan assets</td><td>-30</td><td>-37</td><td>-34</td><td>-32</td><td>-43</td><td>-24</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Amortization:</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>- prior service cost (credit)</td><td>-7</td><td>1</td><td>5</td><td>1</td><td>6</td><td>1</td><td>-4</td><td>-6</td><td>-6</td></tr><tr><td>- actuarial loss</td><td>22</td><td>2</td><td>29</td><td>1</td><td>43</td><td>4</td><td>1</td><td>—</td><td>—</td></tr><tr><td>Net curtailment loss (gain)<sup>(a)</sup></td><td>-5</td><td>4</td><td>—</td><td>—</td><td>—</td><td>—</td><td>-7</td><td>—</td><td>—</td></tr><tr><td>Net settlement loss<sup>(b)</sup></td><td>119</td><td>—</td><td>99</td><td>—</td><td>45</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Net periodic benefit cost<sup>(c)</sup></td><td>$153</td><td>$9</td><td>$165</td><td>$13</td><td>$124</td><td>$21</td><td>$4</td><td>$10</td><td>$10</td></tr><tr><td>Other changes in plan assets and benefit obligations recognized in other comprehensive (income) loss (pretax):</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Actuarial loss (gain)<sup>(d)</sup></td><td>$30</td><td>$-25</td><td>$149</td><td>$33</td><td>$-161</td><td>$-15</td><td>$-21</td><td>$42</td><td>$-31</td></tr><tr><td>Amortization of actuarial gain (loss)</td><td>-134</td><td>-2</td><td>-128</td><td>-1</td><td>-88</td><td>-4</td><td>-1</td><td>—</td><td>—</td></tr><tr><td>Prior service cost (credit)</td><td>-89</td><td>1</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>-42</td><td>—</td></tr><tr><td>Amortization of prior service credit (cost)</td><td>7</td><td>-5</td><td>-5</td><td>-1</td><td>-6</td><td>-1</td><td>13</td><td>6</td><td>6</td></tr><tr><td>Total recognized in other comprehensive (income) loss</td><td>$-186</td><td>$-31</td><td>$16</td><td>$31</td><td>$-255</td><td>$-20</td><td>$-9</td><td>$6</td><td>$-25</td></tr><tr><td>Total recognized in net periodic benefit cost and other comprehensive (income) loss</td><td>$-33</td><td>$-22</td><td>$181</td><td>$44</td><td>$-131</td><td>$1</td><td>$-5</td><td>$16</td><td>$-15</td></tr></table>
<table><tr><td></td><td colspan="6">Pension Benefits</td><td colspan="3">Other Benefits</td></tr><tr><td></td><td colspan="2">2015</td><td colspan="2">2014</td><td colspan="2">2013</td><td>2015</td><td>2014</td><td>2013</td></tr><tr><td>(In millions)</td><td>U.S.</td><td>Int’l</td><td>U.S.</td><td>Int’l</td><td>U.S.</td><td>Int’l</td><td>U.S.</td><td>U.S.</td><td>U.S.</td></tr><tr><td>Weighted average assumptions used to determine benefit obligation:</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Discount rate</td><td>4.04%</td><td>3.90%</td><td>3.71%</td><td>3.70%</td><td>4.28%</td><td>4.60%</td><td>4.36%</td><td>4.01%</td><td>4.85%</td></tr><tr><td>Rate of compensation increase<sup>(a)</sup></td><td>4.00%</td><td>—</td><td>4.00%</td><td>3.60%</td><td>5.00%</td><td>4.90%</td><td>4.00%</td><td>4.00%</td><td>5.00%</td></tr><tr><td>Weighted average assumptions used to determine net periodic benefit cost:</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Discount rate</td><td>3.79%</td><td>3.70%</td><td>3.98%</td><td>4.60%</td><td>3.79%</td><td>4.40%</td><td>3.93%</td><td>4.69%</td><td>4.06%</td></tr><tr><td>Expected long-term return on plan assets</td><td>6.75%</td><td>5.70%</td><td>6.75%</td><td>5.70%</td><td>7.25%</td><td>4.90%</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Rate of compensation increase</td><td>4.00%</td><td>3.60%</td><td>5.00%</td><td>4.90%</td><td>5.00%</td><td>4.50%</td><td>4.00%</td><td>5.00%</td><td>5.00%</td></tr></table>
<table><tr><td></td><td>Year Ended December 31,</td></tr><tr><td>(In millions)</td><td>2015</td><td>2014</td><td>2013</td></tr><tr><td>North America E&P</td><td>$2,553</td><td>$4,698</td><td>$3,649</td></tr><tr><td>International E&P</td><td>368</td><td>534</td><td>456</td></tr><tr><td>Oil Sands Mining<sup>(a)</sup></td><td>-10</td><td>212</td><td>286</td></tr><tr><td>Corporate</td><td>25</td><td>51</td><td>58</td></tr><tr><td>Total capital expenditures</td><td>2,936</td><td>5,495</td><td>4,449</td></tr><tr><td>Change in capital expenditure accrual</td><td>540</td><td>-335</td><td>-6</td></tr><tr><td>Additions to property, plant and equipment</td><td>$3,476</td><td>$5,160</td><td>$4,443</td></tr></table>

Question: When is Interest cost the largest for Pension Benefits Year Ended December 31,for U.S. ?
Answer: 2013