Summary of the Plans' Net Periodic Pension Cost, Benefit Obligations, Funded Status, and Net Balance Sheet Position (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Jan. 01, 2011
Elgin Plan
Net Periodic Pension Cost:
Interest cost	$ 226	$ 231
Expected return on assets	(178)	(167)
Amortization of net loss	125	114
Defined Benefit Plan, Net Periodic Benefit Cost, Total	173	178
Change in Benefit Obligation:
Benefit obligation - beginning of year	4,142	4,095
Interest on benefit obligations	226	231
Actuarial losses	695	85
Net benefit payments	(262)	(269)
Benefit obligation - end of year	4,801	4,142
Change in Plan Assets:
Plan assets at fair value - beginning of year	3,342	3,189
Company contributions	156	118
Investment (loss) gain	(49)	304
Benefit payments and plan expenses	(261)	(269)
Plan assets at fair value - end of year	3,188	3,342
Funded Status:
Unfunded benefit obligation	(1,614)	(799)
Amounts recognized in balance sheet at year end:
Other noncurrent liabilities	(1,614)	(799)
Pre-tax components in accumulated other comprehensive income:
Net actuarial loss	2,102	1,304
Net prior service cost
Net transaction (asset) obligations
Total amount recognized	2,102	1,304
Accumulated Benefit Obligation	4,801	4,142
Assumed discount rate	4.30%	5.50%
Expected return on assets	5.50%	5.50%
Smithville Plan
Net Periodic Pension Cost:
Interest cost	669	635
Expected return on assets	(571)	(523)
Amortization of net loss	203	119
Defined Benefit Plan, Net Periodic Benefit Cost, Total	301	231
Change in Benefit Obligation:
Benefit obligation - beginning of year	11,958	10,821
Interest on benefit obligations	669	635
Actuarial losses	2,978	843
Net benefit payments	(401)	(341)
Benefit obligation - end of year	15,204	11,958
Change in Plan Assets:
Plan assets at fair value - beginning of year	8,253	7,526
Company contributions	225	250
Investment (loss) gain	(257)	818
Benefit payments and plan expenses	(401)	(341)
Plan assets at fair value - end of year	7,820	8,253
Funded Status:
Unfunded benefit obligation	(7,384)	(3,704)
Amounts recognized in balance sheet at year end:
Other noncurrent liabilities	(7,384)	(3,704)
Pre-tax components in accumulated other comprehensive income:
Net actuarial loss	6,291	2,689
Net prior service cost
Net transaction (asset) obligations
Total amount recognized	6,291	2,689
Accumulated Benefit Obligation	15,204	11,958
Assumed discount rate	4.30%	5.50%
Expected return on assets	7.00%	7.00%
Wrexham Plan
Net Periodic Pension Cost:
Interest cost	415
Expected return on assets	(480)
Defined Benefit Plan, Net Periodic Benefit Cost, Total	(65)
Change in Benefit Obligation:
Benefit obligations - acquisitions	13,328
Interest on benefit obligations	415
Actuarial losses	192
Net benefit payments	(246)
Benefit obligation - end of year	13,689
Change in Plan Assets:
Plan assets at fair value - acquisitions	11,798
Company contributions	465
Investment (loss) gain	(499)
Benefit payments and plan expenses	(246)
Plan assets at fair value - end of year	11,518
Funded Status:
Unfunded benefit obligation	(2,170)
Amounts recognized in balance sheet at year end:
Other noncurrent liabilities	(2,170)
Pre-tax components in accumulated other comprehensive income:
Net actuarial loss	1,409
Net prior service cost
Net transaction (asset) obligations
Total amount recognized	1,409
Accumulated Benefit Obligation	13,689
Assumed discount rate	4.70%
Expected return on assets	6.60%
Directors Plans
Net Periodic Pension Cost:
Service cost	1,123	1,091
Interest cost	472	435
Amortization of net loss	507
Pension settlement	13	172
Defined Benefit Plan, Net Periodic Benefit Cost, Total	2,115	1,698
Change in Benefit Obligation:
Benefit obligation - beginning of year	7,028	6,153
Service cost	1,123	1,091
Interest on benefit obligations	472	435
Actuarial losses	3,043
Pension settlement	12	172
Net benefit payments	(300)	(823)
Benefit obligation - end of year	11,378	7,028
Change in Plan Assets:
Company contributions	300	823
Benefit payments and plan expenses	(300)	(823)
Funded Status:
Unfunded benefit obligation	(11,378)	(7,028)
Amounts recognized in balance sheet at year end:
Other noncurrent liabilities	(11,378)	(7,028)
Pre-tax components in accumulated other comprehensive income:
Net actuarial loss	2,536
Net prior service cost
Net transaction (asset) obligations
Total amount recognized	2,536
Accumulated Benefit Obligation	$ 3,999	$ 4,371
Salary growth rate	10.00%	10.00%
Assumed discount rate	4.30%	6.00%