| **Derivative Instruments and Hedging Activities - Effect of Derivative Financial Instruments on Income Statement (Detail) (Not Designated as Hedging Instrument, Interest Rate Contract, USD $)In Thousands, unless otherwise specified** | 12 Months Ended |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------|
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| Other Income                                                                                                                                                                                                                              |            |   |   |
| **Derivative [Line Items]**                                                                                                                                                                                                               |            |   |   |
| Amount of Gain (Loss) Recognized Income on Derivative                                                                                                                                                                                     | $ 247           | $ (79) | $ (94) |
| Cash Flow Hedging                                                                                                                                                                                                                         |            |   |   |
| **Derivative [Line Items]**                                                                                                                                                                                                               |            |   |   |
| Amount of Loss Recognized in Other Comprehensive Income on Derivative (Effective Portion)                                                                                                                                                 | 2,374           | (1,466) |   |
| Cash Flow Hedging | Interest Expense                                                                                                                                                                                                      |            |   |   |
| **Derivative [Line Items]**                                                                                                                                                                                                               |            |   |   |
| Amount of Loss Reclassified from Other Comprehensive Income Into Income (Effective Portion)                                                                                                                                               | $ (935)         | $ (217) |   |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The effective portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments that was recognized in other comprehensive income during the current period.
+ References
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| X                                                                                                                                                       |
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