New Accounting Pronouncements Adopted (Policies)	3 Months Ended
Mar. 31, 2012
New Accounting Pronouncements Adopted [Abstract]
Goodwill Impairment	In September 2011, the FASB issued amendments intended to simplify how entities test goodwill for impairment. The amendments permit an entity to first assess qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount as a basis for determining whether it is necessary to perform the two-step goodwill impairment test. Under the guidance, an entity is not required to calculate the fair value of a reporting unit unless the entity determines that it is more likely than not that its fair value is less than its carrying value. The amendments are effective for interim and annual periods beginning after December 15, 2011, with early adoption permitted. The Corporation adopted the accounting standard as of January 1, 2012, as required, with no material impact on its results of operations, financial position, and liquidity. See Note 7 for additional disclosures required under this accounting standard.
Fair value measurement	In May 2011, the FASB issued guidance on measuring fair value to create common fair value measurement and disclosure requirements in U.S. GAAP and IFRS. The amendments change the wording used to describe many of the requirements for measuring fair value and for disclosing information about fair value measurements. The amendments also clarify the Board's intent about the application of existing fair value measurement and disclosure requirements. The amendments are effective for interim and annual periods beginning after December 15, 2011. The Corporation adopted the accounting standard as of January 1, 2012, with no material impact on its results of operations, financial position, and liquidity. See Note 12 for additional disclosures required under this accounting standard.
Comprehensive Income	In June 2011, the FASB issued guidance to improve the comparability, consistency and transparency of financial reporting and to increase the prominence of items reported in other comprehensive income. The amendments require that all nonowner changes in stockholders' equity be presented either in a single continuous statement of comprehensive income or in two separate but consecutive statements. The amendments do not change the items that must be reported in other comprehensive income or when an item of other comprehensive income must be reclassified to net income. The amendments are effective for interim and annual periods beginning after December 15, 2011 with retrospective application. The Corporation adopted the accounting standard as of January 1, 2012, as required, with no material impact on its results of operations, financial position, and liquidity. In December 2011, the FASB decided that the requirement to present items that are reclassified from other comprehensive income to net income alongside their respective components of net income and other comprehensive income will be deferred. Therefore, those requirements have not been adopted at this time.
Securities Sold Under Agreements To Repurchase Policy	In April 2011, the FASB issued guidance which clarifies the definition of effective control for determining whether a repurchase agreement is accounted for as a sale or secured borrowing. The amendments in the guidance remove from the assessment of effective control both the criterion requiring the transferor to have the ability to repurchase or redeem the financial assets on substantially the agreed upon terms and the collateral maintenance implementation guidance related to that criterion. Other criteria applicable to the assessment of effective control are not changed by the amendments in the update. The guidance is effective for interim and annual periods beginning on or after December 15, 2011. The Corporation adopted the accounting standard as of January 1, 2012, as required, with no material impact on its results of operations, financial position, and liquidity.

New Accounting Pronouncements Adopted (Policies)

3 Months Ended

Mar. 31, 2012

New Accounting Pronouncements Adopted [Abstract]

In September 2011, the FASB issued amendments intended to simplify how entities test goodwill for impairment. The amendments permit an entity to first assess qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount as a basis for determining whether it is necessary to perform the two-step goodwill impairment test. Under the guidance, an entity is not required to calculate the fair value of a reporting unit unless the entity determines that it is more likely than not that its fair value is less than its carrying value. The amendments are effective for interim and annual periods beginning after December 15, 2011, with early adoption permitted. The Corporation adopted the accounting standard as of January 1, 2012, as required, with no material impact on its results of operations, financial position, and liquidity. See Note 7 for additional disclosures required under this accounting standard.

Fair value measurement

In May 2011, the FASB issued guidance on measuring fair value to create common fair value measurement and disclosure requirements in U.S. GAAP and IFRS. The amendments change the wording used to describe many of the requirements for measuring fair value and for disclosing information about fair value measurements. The amendments also clarify the Board's intent about the application of existing fair value measurement and disclosure requirements. The amendments are effective for interim and annual periods beginning after December 15, 2011. The Corporation adopted the accounting standard as of January 1, 2012, with no material impact on its results of operations, financial position, and liquidity. See Note 12 for additional disclosures required under this accounting standard.

Comprehensive Income

In June 2011, the FASB issued guidance to improve the comparability, consistency and transparency of financial reporting and to increase the prominence of items reported in other comprehensive income. The amendments require that all nonowner changes in stockholders' equity be presented either in a single continuous statement of comprehensive income or in two separate but consecutive statements. The amendments do not change the items that must be reported in other comprehensive income or when an item of other comprehensive income must be reclassified to net income. The amendments are effective for interim and annual periods beginning after December 15, 2011 with retrospective application. The Corporation adopted the accounting standard as of January 1, 2012, as required, with no material impact on its results of operations, financial position, and liquidity. In December 2011, the FASB decided that the requirement to present items that are reclassified from other comprehensive income to net income alongside their respective components of net income and other comprehensive income will be deferred. Therefore, those requirements have not been adopted at this time.

Securities Sold Under Agreements To Repurchase Policy

In April 2011, the FASB issued guidance which clarifies the definition of effective control for determining whether a repurchase agreement is accounted for as a sale or secured borrowing. The amendments in the guidance remove from the assessment of effective control both the criterion requiring the transferor to have the ability to repurchase or redeem the financial assets on substantially the agreed upon terms and the collateral maintenance implementation guidance related to that criterion. Other criteria applicable to the assessment of effective control are not changed by the amendments in the update. The guidance is effective for interim and annual periods beginning on or after December 15, 2011. The Corporation adopted the accounting standard as of January 1, 2012, as required, with no material impact on its results of operations, financial position, and liquidity.