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Employee Benefits (Details) £ in Millions, $ in Millions | 3 Months Ended
--- | ---
Mar. 31, 2019 USD ($) | Mar. 31, 2018 GBP (£) | Mar. 31, 2018 USD ($)
U.K. |  |  |
Defined Benefit Plan Disclosure |  |  |
Interest cost | $ 28 |  | $ 29
Expected return on plan assets, net of administration expenses | (49) |  | (51)
Amortization of prior-service cost | 1 |  | 0
Amortization of net actuarial loss | 7 |  | 8
Net periodic (benefit) cost | (13) |  | (14)
Loss on pension settlement | 0 |  | 7
Total net periodic (benefit) cost | (13) |  | (7)
Payment for settlement |  | £ 48 | 68
Benefit obligation period increase (decrease) |  | (44) | (63)
Benefit obligation, (increase) decrease for settlement |  | £ 5 | 7
Estimate of contributions to defined benefit pension plans for the current fiscal year | 80 |  |
Contributions made to defined benefit pension plans | 23 |  | 23
U.S. |  |  |
Defined Benefit Plan Disclosure |  |  |
Interest cost | 27 |  | 25
Expected return on plan assets, net of administration expenses | (34) |  | (36)
Amortization of prior-service cost | 1 |  | 0
Amortization of net actuarial loss | 13 |  | 15
Net periodic (benefit) cost | 7 |  | 4
Loss on pension settlement | 0 |  | 0
Total net periodic (benefit) cost | 7 |  | 4
Estimate of contributions to defined benefit pension plans for the current fiscal year | 46 |  |
Contributions made to defined benefit pension plans | 17 |  | 17
Other |  |  |
Defined Benefit Plan Disclosure |  |  |
Interest cost | 7 |  | 7
Expected return on plan assets, net of administration expenses | (10) |  | (12)
Amortization of prior-service cost | 0 |  | 0
Amortization of net actuarial loss | 3 |  | 3
Net periodic (benefit) cost | 0 |  | (2)
Loss on pension settlement | 0 |  | 0
Total net periodic (benefit) cost | 0 |  | (2)
Estimate of contributions to defined benefit pension plans for the current fiscal year | 19 |  |
Contributions made to defined benefit pension plans | $ 7 |  | $ 8

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