Employee Benefit Plans - Return on Current and Target Asset Allocation (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Pension plan assets	$ 18,367		$ 14,687
Cash and other investments
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Pension plan assets	716		2,905
Fixed income securities
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Pension plan assets	3,328		860
Equity securities
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Pension plan assets	14,323	[1]	10,922	[1]
Level 1
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Pension plan assets	14,718		11,346
Level 1 | Cash and other investments
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Pension plan assets	716		2,905
Level 1 | Fixed income securities
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Pension plan assets	3,328
Level 1 | Equity securities
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Pension plan assets	10,674	[1]	8,441	[1]
Level 2
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Pension plan assets	3,649		3,341
Level 2 | Fixed income securities
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Pension plan assets			860
Level 2 | Equity securities
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Pension plan assets	$ 3,649	[1]	$ 2,481	[1]

[1] Represents mutual funds and commingled accounts which invest primarily in equities, but may also hold fixed income securities, cash and other investments.