Summary of Significant Accounting Policies - Additional Information (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Schedule Of Significant Accounting Policies [Line Items]
Percentage of unrealized gains and losses used to determine market related value of plan asset	20.00%
Moving average period to determine market value of plan assets	5 years
Deferred income tax liability	$ 0
Weighted average of common shares outstanding	10,406,478	10,389,678	10,393,159
Stock Option [Member]
Schedule Of Significant Accounting Policies [Line Items]
Weighted average outstanding stock options	781,325	671,977	544,342
Minimum [Member]
Schedule Of Significant Accounting Policies [Line Items]
Investments in joint ventures	20.00%
Defined benefit plan actuarial gain loss percentage	10.00%
Minimum [Member] | Land Improvements [Member]
Schedule Of Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful life	15 years
Minimum [Member] | Buildings [Member]
Schedule Of Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful life	25 years
Minimum [Member] | Machinery and Equipment [Member]
Schedule Of Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful life	3 years
Maximum [Member]
Schedule Of Significant Accounting Policies [Line Items]
Investments in joint ventures	50.00%
Defined benefit plan actuarial gain loss percentage	10.00%
Maximum [Member] | Land Improvements [Member]
Schedule Of Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful life	20 years
Maximum [Member] | Buildings [Member]
Schedule Of Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful life	50 years
Maximum [Member] | Machinery and Equipment [Member]
Schedule Of Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful life	25 years