Accumulated Other Comprehensive Loss - Summary of Reclassifications Out of Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss), Pre-Tax Amount	$ 151	$ (192)	$ 871	$ 613
Other comprehensive income (loss), Tax Expense (Benefit)	(57)	(48)	(309)	(242)
Other comprehensive income (loss) before reclassification adjustments, After-Tax Amount	200	(192)	576	(43)
Other comprehensive income (loss), Reclassification adjustments, After-Tax Amount	(106)	48	(14)	414
Other comprehensive income (loss)	94	(144)	562	371
Unrealized Gains (Losses) on Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss) before reclassification adjustments, Pre-Tax Amount	458	(312)	769	18
Other comprehensive income (loss), Reclassification adjustments, Pre-Tax Amount	(106)	113	(14)	684
Other comprehensive income (loss), Pre-Tax Amount	352	(199)	755	702
Other comprehensive income (loss) before reclassification adjustments, Tax Expense (Benefit)	(128)	(112)	(269)	(7)
Other comprehensive income (loss), Reclassification adjustments, Tax Expense (Benefit)		65		(270)
Other comprehensive income (loss), Tax Expense (Benefit)	(128)	(47)	(269)	(277)
Other comprehensive income (loss) before reclassification adjustments, After-Tax Amount	330	(200)	500	11
Other comprehensive income (loss), Reclassification adjustments, After-Tax Amount	(106)	48	(14)	414
Other comprehensive income (loss)	224	(152)	486	425
Unrealized Gains (Losses) on Investments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss) before reclassification adjustments, Pre-Tax Amount	(201)	7	116	(89)
Other comprehensive income (loss), Pre-Tax Amount	(201)	7	116	(89)
Other comprehensive income (loss) before reclassification adjustments, Tax Expense (Benefit)	71	(1)	(40)	35
Other comprehensive income (loss), Tax Expense (Benefit)	71	(1)	(40)	35
Other comprehensive income (loss) before reclassification adjustments, After-Tax Amount	(130)	8	76	(54)
Other comprehensive income (loss)	$ (130)	$ 8	$ 76	$ (54)