Other-than-temporary Impairment Not Previously Recognized (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Jun. 30, 2013
Other than temporary impairment credit losses recognized in earnings [Roll Forward]
Balance at March 31, 2013	$ 552
Other-than-temporary impairment not previously recognized	0
Balance at June 30, 2013	$ 552

The change during the reporting period in the cumulative amount of credit losses recognized in earnings related to debt securities held for which a portion of an other than temporary impairment (OTTI) was recognized in other comprehensive income (a component of shareholders' equity).

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27340-111563

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration