9. Goodwill and Other Intangible Assets  Goodwill and other intangible assets are summarized as follows: As of December 31, 2002 2001 Gross Accumulated Net Gross Accumulated Net (In thousands) Amount Amortization Amount Amount Amortiziation Amount Amortizable intangible assets: Mortgage servicing rights, net . . . $ 92,525 $29,881 $ 62,644  $ 76,782 $18,521 $ 58,261 Deposit base intangibles . . . . . . . 21,180 13,607 7,573 21,180 11,936 9,244 Total . . . . . . . . . . . . . . . . . . $113,705 $43,488  $ 70,217  $ 97,962 $30,457 $ 67,505 Unamortizable intangible assets: Goodwill (included in  Banking Segment)  . . . . . . . . . . $145,462 $145,462 $145,462 $145,462 (In thousands) Mortgage Deposit Base Estimated Amortization Expense: Servicing Rights Intangibles Total For the year ended December 31, 2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 16,899 $ 1,666 $ 18,565 For the year ended December 31, 2004 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13,519 1,662 15,181 For the year ended December 31, 2005 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10,815 1,659 12,474 For the year ended December 31, 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8,652 1,630 10,282 For the year ended December 31, 2007 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6,922 913 7,835 Year Ended December 31, (In thousands) 2002 2001 2000 Mortgage servicing rights at beginning of year . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 63,607 $ 41,032 $ 23,560 Purchases and originations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39,757 39,139 22,798 Amortization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (22,874) (16,564) (5,326) Impairment write-down . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (8,500) – – Mortgage servicing rights at end of year . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71,990 63,607 41,032 Valuation allowance at beginning of year . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5,346 946 946 Provision for impairment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12,500 4,400 – Impairment write-down . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (8,500) – –  Valuation allowance at end of year . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9,346 5,346 946 Mortgage servicing rights, net . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 62,644 $ 58,261 $ 40,086 The activity in mortgage servicing rights and the related valuation allowance is summarized as follows: 10. Mortgage Banking Amortization expense for intangible assets was $24.5 million and $26.3 million for the years ended December 31, 2002 and 2001, respec- tively. The following table shows the estimated future amortization expense for intangible assets based on existing asset balances and the inter- est rate environment as of December 31, 2002. The Company’s actual amortization expense in any given period may be significantly different from the estimated amounts depending upon the addition of new intangible assets, changes in mortgage interest rates, prepay- ment rates and market conditions. page 58