Accounting pronouncements	3 Months Ended
Mar. 31, 2012
Accounting Policies [Abstract]
Description of New Accounting Pronouncements Not Yet Adopted and Recently Adopted [Text Block]	Accounting pronouncements Recently adopted accounting pronouncements ASU No. 2011-04, Fair Value Measurement (Topic 820): Amendments to Achieve Common Fair Value Measurement and Disclosure Requirements in U.S. GAAP and IFRS The Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) No. 2011-04, Fair Value Measurement (Topic 820): Amendments to Achieve Common Fair Value Measurement and Disclosure Requirements in U.S. GAAP and IFRS. The guidance amends and converges U.S. GAAP and International Financial Reporting Standards (“IFRS”) requirements for measuring amounts at fair value as well as disclosures regarding these measurements. The update became effective in the fourth quarter of 2011. The adoption of this Topic did not have a material impact on the Company’s consolidated financial statements. ASU No. 2011-05, Comprehensive Income (Topic 220): Presentation of Comprehensive Income The FASB issued ASU No. 2011-05, Comprehensive Income (Topic 220): Presentation of Comprehensive Income in June 2011. This update changes the requirements for the presentation of other comprehensive income, eliminating the option to present components of other comprehensive income as part of the statement of stockholders’ equity, among other items. The guidance requires that all non-owner changes in stockholders’ equity be presented in either a single continuous statement of comprehensive income or in two separate but consecutive statements. The FASB deferred the requirement for companies to present reclassification adjustments for each component of other comprehensive income on the face of the financial statements in ASU No. 2011-12; however, the presentation requirement under ASU No. 2011-05 is effective for fiscal years and interim periods beginning after December 15, 2011. Since the update only requires a change in presentation, the early adoption of this Topic in the fourth quarter of 2011 did not have a material impact on the Company’s consolidated financial statements. ASU No. 2011-08, Intangibles - Goodwill and Other (Topic 350): Testing Goodwill for Impairment The FASB issued ASU No. 2011-08, Intangibles - Goodwill and Other (Topic 350): Testing Goodwill for Impairment in September 2011. This update simplifies how entities test goodwill for impairment. Under the amendments in this update, 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 amount by assessing qualitative factors. The amendments are effective for annual and interim goodwill impairment tests performed for fiscal years beginning after December 15, 2011 with early adoption permitted. The early adoption of this Topic in the fourth quarter of 2011 did not have a material impact on the Company’s consolidated financial statements.

Accounting pronouncements

Recently adopted accounting pronouncements

ASU No. 2011-04, Fair Value Measurement (Topic 820): Amendments to Achieve Common Fair Value Measurement and Disclosure Requirements in U.S. GAAP and IFRS

The Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) No. 2011-04, Fair Value Measurement (Topic 820): Amendments to Achieve Common Fair Value Measurement and Disclosure Requirements in U.S. GAAP and IFRS. The guidance amends and converges U.S. GAAP and International Financial Reporting Standards (“IFRS”) requirements for measuring amounts at fair value as well as disclosures regarding these measurements. The update became effective in the fourth quarter of 2011. The adoption of this Topic did not have a material impact on the Company’s consolidated financial statements.

ASU No. 2011-05, Comprehensive Income (Topic 220): Presentation of Comprehensive Income

The FASB issued ASU No. 2011-05, Comprehensive Income (Topic 220): Presentation of Comprehensive Income in June 2011. This update changes the requirements for the presentation of other comprehensive income, eliminating the option to present components of other comprehensive income as part of the statement of stockholders’ equity, among other items. The guidance requires that all non-owner changes in stockholders’ equity be presented in either a single continuous statement of comprehensive income or in two separate but consecutive statements. The FASB deferred the requirement for companies to present reclassification adjustments for each component of other comprehensive income on the face of the financial statements in ASU No. 2011-12; however, the presentation requirement under ASU No. 2011-05 is effective for fiscal years and interim periods beginning after December 15, 2011. Since the update only requires a change in presentation, the early adoption of this Topic in the fourth quarter of 2011 did not have a material impact on the Company’s consolidated financial statements.

ASU No. 2011-08, Intangibles - Goodwill and Other (Topic 350): Testing Goodwill for Impairment

The FASB issued ASU No. 2011-08, Intangibles - Goodwill and Other (Topic 350): Testing Goodwill for Impairment in September 2011. This update simplifies how entities test goodwill for impairment. Under the amendments in this update, 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 amount by assessing qualitative factors. The amendments are effective for annual and interim goodwill impairment tests performed for fiscal years beginning after December 15, 2011 with early adoption permitted. The early adoption of this Topic in the fourth quarter of 2011 did not have a material impact on the Company’s consolidated financial statements.