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Comprehensive Income (Tables) | 3 Months Ended | 6 Months Ended
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Jun. 30, 2011 | Jun. 30, 2010 | Jun. 30, 2011 | Jun. 30, 2010
Comprehensive Income [Abstract] |  |  |  |
Components of Comprehensive Income-Gross and Net of Tax |
Second Quarter 2011 |  |  |  |  |  |
($ in thousands) |  | Gross |  | Tax |  | Net
Net income | $ | 1,221 |  | (1,104) |  | 2,325
Components of OCI: |  |  |  |  |  |
Unrealized gains on securities: |  |  |  |  |  |
Unrealized holding gains during the period |  | 30,099 |  | 10,536 |  | 19,563
Portion of OTTI recognized in OCI |  | 418 |  | 146 |  | 272
Amortization of net unrealized gains on HTM securities |  | (1,258) |  | (441) |  | (817)
Reclassification adjustment for gains included in net |  |  |  |  |  |
income |  | (2,144) |  | (751) |  | (1,393)
Net unrealized gains |  | 27,115 |  | 9,490 |  | 17,625
Defined benefit pension and post-retirement plans: |  |  |  |  |  |
Reversal of amortization items: |  |  |  |  |  |
Net actuarial loss |  | 1,104 |  | 386 |  | 718
Prior service cost |  | 38 |  | 13 |  | 25
Defined benefit pension and post-retirement plans |  | 1,142 |  | 399 |  | 743
Comprehensive income | $ | 29,478 |  | 8,785 |  | 20,693
Second Quarter 2010 |  |  |  |  |  |
($ in thousands) |  | Gross |  | Tax |  | Net
Net income | $ | 20,810 |  | 2,044 |  | 18,766
Components of other comprehensive income: |  |  |  |  |  |
Unrealized gains on securities: |  |  |  |  |  |
Unrealized holding gains during the period |  | 31,498 |  | 11,024 |  | 20,474
Portion of OTTI recognized in OCI |  | 3,617 |  | 1,265 |  | 2,352
Amortization of net unrealized gains on HTM securities |  | (802) |  | (280) |  | (522)
Reclassification adjustment for losses included in net |  |  |  |  |  |
income |  | 783 |  | 274 |  | 509
Net unrealized gains |  | 35,096 |  | 12,283 |  | 22,813
Defined benefit pension and post-retirement plans: |  |  |  |  |  |
Reversal of amortization items: |  |  |  |  |  |
Net actuarial loss |  | 1,172 |  | 411 |  | 761
Prior service cost |  | 38 |  | 13 |  | 25
Defined benefit pension and post-retirement plans |  | 1,210 |  | 424 |  | 786
Comprehensive income | $ | 57,116 |  | 14,751 |  | 42,365
Six Months 2011 |  |  |  |  |  |
($ in thousands) |  | Gross |  | Tax |  | Net
Net income | $ | 28,993 |  | 5,119 |  | 23,874
Components of OCI: |  |  |  |  |  |
Unrealized gains on securities: |  |  |  |  |  |
Unrealized holding gains during the period |  | 29,166 |  | 10,209 |  | 18,957
Portion of OTTI recognized in OCI |  | 598 |  | 209 |  | 389
Amortization of net unrealized gains on HTM securities |  | (2,433) |  | (852) |  | (1,581)
Reclassification adjustment for gains included in net |  |  |  |  |  |
income |  | (7,893) |  | (2,763) |  | (5,130)
Net unrealized gains |  | 19,438 |  | 6,803 |  | 12,635
Defined benefit pension and post-retirement plans: |  |  |  |  |  |
Reversal of amortization items: |  |  |  |  |  |
Net actuarial loss |  | 2,209 |  | 773 |  | 1,436
Prior service cost |  | 75 |  | 26 |  | 49
Defined benefit pension and post-retirement plans |  | 2,284 |  | 799 |  | 1,485
Comprehensive income | $ | 50,715 |  | 12,721 |  | 37,994
Six Months 2010 |  |  |  |  |  |
($ in thousands) |  | Gross |  | Tax |  | Net
Net income | $ | 27,241 |  | 2,672 |  | 24,569
Components of other comprehensive income: |  |  |  |  |  |
Unrealized gains on securities: |  |  |  |  |  |
Unrealized holding gains during the period |  | 46,698 |  | 16,344 |  | 30,354
Portion of OTTI recognized in OCI |  | 5,892 |  | 2,062 |  | 3,830
Amortization of net unrealized gains on HTM securities |  | (6,555) |  | (2,294) |  | (4,261)
Reclassification adjustment for gains included in net |  |  |  |  |  |
income |  | (1,614) |  | (565) |  | (1,049)
Net unrealized gains |  | 44,421 |  | 15,547 |  | 28,874
Defined benefit pension and post-retirement plans: |  |  |  |  |  |
Reversal of amortization items: |  |  |  |  |  |
Net actuarial loss |  | 2,098 |  | 735 |  | 1,363
Prior service cost |  | 75 |  | 26 |  | 49
Defined benefit pension and post-retirement plans |  | 2,173 |  | 761 |  | 1,412
Comprehensive income | $ | 73,835 |  | 18,980 |  | 54,855
Components of Accumulated Other Comprehensive Income |  |  |
June 30, 2011 |  |  |  | Defined |  |
|  | Net Unrealized Gain (Loss) |  | Benefit |  |
|  | OTTI |  | HTM |  | All |  | Pension and Post-Retirement |  | Total Accumulated
($ in thousands) |  | Related |  | Related |  | Other |  | Plans |  | OCI
Balance, December 31, 2010 | $ | (4,593) |  | 11,144 |  | 47,316 |  | (46,843) |  | 7,024
Changes in component during period |  | 389 |  | (2,228) |  | 14,474 |  | 1,485 |  | 14,120
Balance, June 30, 2011 | $ | (4,204) |  | 8,916 |  | 61,790 |  | (45,358) |  | 21,144

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