Consolidated Statements of Income (Parenthetical) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2013	Mar. 31, 2012
Consolidated Statements of Income
Impairment charges, other-than-temporary impairment charges	$ 968	$ 1,650
Impairment charges, other comprehensive income	$ 658	$ 1,464

Before tax amount of other comprehensive income (loss) attributable to both parent entity and noncontrolling interest.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 1A

-URI http://asc.fasb.org/extlink&oid=20435746&loc=SL7669619-108580

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 1B

-URI http://asc.fasb.org/extlink&oid=20435746&loc=SL7669625-108580

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 323

-SubTopic 10

-Section 45

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=16385135&loc=d3e33775-111570

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