Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 2,546,000us-gaap_NetIncomeLoss	$ 2,527,000us-gaap_NetIncomeLoss
Other comprehensive income, net of tax:
Foreign currency translation	(132,000)	(34,000)
Net unrealized loss on available-for-sale securities		(130,000)
Net unrealized gain reclassified into income on sale of available-for-sale securities		(66,000)
Comprehensive income	$ 2,414,000us-gaap_ComprehensiveIncomeNetOfTax	$ 2,297,000us-gaap_ComprehensiveIncomeNetOfTax

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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Amount after tax and reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

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Amount after tax of reclassification adjustment from accumulated other comprehensive income for unrealized gain (loss) realized upon the sale of available-for-sale securities.

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Amount after tax, before reclassification adjustments, of unrealized holding gain (loss) on available-for-sale securities.

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