Other Comprehensive Income - Summary of Other Comprehensive Income and Tax Impact (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Other Comprehensive Income Loss Net Of Tax Period Increase Decrease [Abstract]
Net unrealized gain (loss) on available-for-sale securities, net of income taxes	$ 4	$ 62	$ (326)	$ 151
Net unrealized gain (loss) on interest rate swaps, net of income taxes	176	(22)	626	71
Foreign currency translation	(6)	(3)	(12)	(5)
Total other comprehensive income	$ 174	$ 37	$ 288	$ 217

Amount after tax and reclassification adjustments, of appreciation (loss) in value of unsold available-for-sale securities. Excludes amounts related to other than temporary impairment (OTTI) loss.

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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 and reclassification adjustments of other comprehensive income (loss).

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Amount before tax of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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