Income Taxes - Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Uncertainties [Abstract]
Unrecognized tax benefits at January 1	$ 2,300us-gaap_UnrecognizedTaxBenefits	$ 2,710us-gaap_UnrecognizedTaxBenefits	$ 2,516us-gaap_UnrecognizedTaxBenefits
Additions for tax positions of prior periods	25		110
Additions for tax positions of current period	182	286	49
Additions due to acquisitions			509
Settlements with taxing authorities		(406)
Lapse of applicable statute of limitations		(290)	(330)
Adjustments to tax positions	(36)		(144)
Unrecognized tax benefits at December 31	$ 2,471us-gaap_UnrecognizedTaxBenefits	$ 2,300us-gaap_UnrecognizedTaxBenefits	$ 2,710us-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

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Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities.

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-Publisher FASB

-Name Accounting Standards Codification

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Amount of increase in unrecognized tax benefits resulting from acquisitions.

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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.

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-Name Accounting Standards Codification

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

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The net amount of all increases and decreases in unrecognized tax benefits for the period.

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

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