Description of Business and Summary of Significant Accounting Policies (Tables)
 12 Months Ended
Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]  
Summary Cumulative Catch-Up Adjustments
Cumulative catch-up adjustments for the years ended December 31, 2017, 2016 and 2015 are presented in the following table:
 
 
Year Ended December 31,
(In thousands)
 
2017
 
2016
 
2015
Favorable adjustments
 
$
18,256

 
$
15,296

 
$
9,721

Unfavorable adjustments
 
(6,704
)
 
(7,837
)
 
(11,641
)
Net favorable (unfavorable) adjustments
 
$
11,552

 
$
7,459

 
$
(1,920
)
Schedule of Useful Lives
Depreciation and amortization is generally computed using either an accelerated or straight-line method and is based on estimated useful lives or lease term as follows:
 
 
Years
Buildings and improvements
 
5 – 40
Machinery and equipment
 
3 – 10
Furniture, fixtures, and office equipment
 
3 – 7
Property, plant and equipment, net consisted of the following at December 31:
(In thousands)

2017
 
2016
Buildings and improvements

$
5,197

 
$
5,230

Machinery and equipment

5,556

 
4,422

Furniture, fixtures and office equipment

4,895

 
3,721

Property, plant and equipment, gross

15,648

 
13,373

Less: accumulated depreciation and amortization

(11,915
)
 
(10,312
)
Property, plant and equipment, net

$
3,733

 
$
3,061