Fair Value Measurements - Assets or Liabilities Recorded at Fair Value (Detail) - Fair Value Based on Significant Other Observable Inputs (Level 2) [Member] - USD ($) $ in Thousands  | 
Dec. 31, 2016  | 
Dec. 31, 2015  | 
|---|---|---|
| Assets: | ||
| Cash surrender value of life insurance policies | $ 31,475 | $ 29,055 | 
| Cash flow swaps designated as hedges | 2,772 | |
| Total assets | 34,247 | 29,055 | 
| Liabilities: | ||
| Cash flow swaps designated as hedges | 6,135 | 9,094 | 
| Cash flow swaps not designated as hedges | 346 | 913 | 
| Deferred compensation plan | 14,824 | 13,551 | 
| Total liabilities | $ 21,305 | $ 23,558 | 
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- Definition Deferred compensation plan liability fair value disclosure. No definition available. 
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- Definition Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- References No definition available. 
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- Definition Fair value portion of the amount that could be realized under a life insurance contract or contracts owned by the entity, commonly known as corporate-owned life insurance (COLI) or bank-owned life insurance (BOLI). Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Fair value as of the balance sheet date of all interest rate derivative assets designated as cash flow hedging instruments. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Fair value as of the balance sheet date of all interest rate derivative liabilities designated as cash flow hedging instruments. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Fair value as of the balance sheet date of all derivative liabilities not designated as hedging instruments. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Fair value of financial and nonfinancial obligations. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- References No definition available. 
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- Details 
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