The Company’s other intangible assets and related accumulated amortization is as follows: April 30, 2003 April 30, 2002 Acquisition Accumulated Acquisition Accumulated (Dollars in thousands) Cost Amortization Net Cost Amortization Net Finite-lived intangible assets: Patents $ 1,000 $ 91 $ 909 $  — $ — $  — Customer lists and formulas 3,887 583 3,304 3,887 194 3,693 Total intangible assets subject  to amortization $ 4,887 $674 $ 4,213 $ 3,887 $194 $ 3,693 Indefinite-lived intangible assets: Trademarks $316,196 $ — $316,196 $11,132 $ — $11,132 Total intangible assets not subject  to amortization $316,196 $ — $316,196 $11,132 $ — $11,132 Total other intangible assets $321,083 $674 $320,409 $15,019 $194 $14,825 Amortization expense for finite-lived intangible assets was approximately $480,000 in fiscal 2003. Based on the current amount of intangible assets subject to amortization, the estimated amortization expense for each of the succeeding five years is $490,000.  Pursuant to Statement of Financial Accounting Standards No. 142,  Goodwill and Other Intangible Assets , the Company is required to review goodwill and indefinite-lived intangible assets at least annually for impairment. The annual impairment review of all appropriate assets was performed as of February 1, 2003.  Note H: Pensions and Other Postretirement Benefits The Company has pension plans covering substantially all of its domestic employees. Benefits are based on the employee’s years of service and compensation. The Company’s plans are funded in conformity with the funding requirements of applicable government regulations.  In addition to providing pension benefits, the Company sponsors several unfunded, defined postretirement plans that provide health care and life insurance benefits to substantially all active and retired domestic employees not covered by certain collective bargaining agreements, and their covered dependents and beneficiaries. These plans are con- tributory, with retiree contributions adjusted periodically, and contain other cost-sharing features, such as deductibles and coinsurance. Covered employees generally are eligible for these benefits when they reach age 55 and have attained ten years of credited service. Net periodic benefit cost included the following components: (Dollars in thousands) Defined Benefit Pension Plans  Other Postretirement Benefits Year Ended April 30, 2003 2002 2001 2003 2002 2001 Service cost  $3,121 $2,414 $2,133 $ 695 $ 506 $424 Interest cost  5,976 5,504 5,303 990 737 673 Expected return on plan assets (6,106) (6,444) (6,571) — — — Amortization of prior service cost (credit) 1,239 1,087 1,086 (45) (61) (61) Amortization of initial net asset (234)  (234) (142) — — — Recognized net actuarial loss (gain) 131 (177) (823) (78) (160) (218) Net periodic benefit cost $4,127 $2,150 $ 986 $1,562 $1,022 $818 32