Employee Benefit Plans - Schedule of Fair Value of Pension Assets (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
Cash	$ 6,385	$ 1,864
Investment securities	33,773
Total assets at fair value	332,203	288,714	255,305
Equity securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investment securities	189,852	192,555
Fixed income securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investment securities	23,273	65,414
Absolute return strategy fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Investment securities	93,343
Other types of investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Investment securities	19,350	28,881
Quoted Prices in Active Markets for Identical Assets or Liabilities (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Cash	6,385	1,864
Total assets at fair value	35,538	25,117
Quoted Prices in Active Markets for Identical Assets or Liabilities (Level 1) [Member] | Equity securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investment securities	29,153	23,253
Significant Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	293,571	253,347
Significant Observable Inputs (Level 2) [Member] | Equity securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investment securities	160,699	169,302
Significant Observable Inputs (Level 2) [Member] | Fixed income securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investment securities	23,273	65,414
Significant Observable Inputs (Level 2) [Member] | Absolute return strategy fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Investment securities	93,343
Significant Observable Inputs (Level 2) [Member] | Other types of investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Investment securities	16,256	18,631
Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	3,094	10,250
Significant Unobservable Inputs (Level 3) [Member] | Other types of investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Investment securities	$ 3,094	$ 10,250