- Unrecognized Tax Benefits (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Summary of reconciliation of change in unrecognized tax benefits
Balance at beginning of year	$ 1,139us-gaap_UnrecognizedTaxBenefits	$ 1,149us-gaap_UnrecognizedTaxBenefits	$ 1,053us-gaap_UnrecognizedTaxBenefits
Additions based on tax positions	193	398	381
Reductions for tax positions of prior years	(349)	0	0
Reductions due to lapses of statutes of limitations	(204)	(408)	(285)
Balance at end of year	$ 779us-gaap_UnrecognizedTaxBenefits	$ 1,139us-gaap_UnrecognizedTaxBenefits	$ 1,149us-gaap_UnrecognizedTaxBenefits

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Amount of unrecognized tax benefits pertaining to uncertain tax positions taken in tax returns.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Unrecognized Tax Benefit

-URI http://asc.fasb.org/extlink&oid=6527854

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-Name Accounting Standards Codification

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Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return.

+ References

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

-Publisher FASB

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Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations.

+ References

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

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