Accumulated Other Comprehensive Loss - Schedule of Components of Accumulated Other Comprehensive Loss (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), Beginning Balance	$ (1,833)	$ (1,261)
Other comprehensive income before reclassifications	117	45
Amounts reclassified from accumulated other comprehensive income (loss)	(23)	21
Other comprehensive income	94	66
Accumulated other comprehensive income (loss), Ending Balance	(1,739)	(1,195)
Defined Benefit Pension Items [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), Beginning Balance	(1,862)	(1,275)
Other comprehensive income before reclassifications	56	36
Amounts reclassified from accumulated other comprehensive income (loss)	53	28
Other comprehensive income	109	64
Accumulated other comprehensive income (loss), Ending Balance	(1,753)	(1,211)
Gains (Losses) on Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), Beginning Balance	29	14
Other comprehensive income before reclassifications	61	9
Amounts reclassified from accumulated other comprehensive income (loss)	(76)	(7)
Other comprehensive income	(15)	2
Accumulated other comprehensive income (loss), Ending Balance	$ 14	$ 16

- Definition

Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

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