Contracts in Progress (Tables)
 12 Months Ended
Dec. 31, 2015
Contractors [Abstract]  
Schedule of Contract Cost and Recognized Income Not Yet Billed and Related Amounts
Contract cost and recognized income not yet billed and related amounts billed as of December 31, 2015 and 2014 were as follows (in thousands): 
 
 
December 31,
 
 
2015
 
2014
Cost incurred on contracts in progress
 
$
567,144

 
$
870,685

Recognized income
 
50,812

 
68,459

 
 
617,956

 
939,144

Progress billings and advance payments
 
(607,397
)
 
(923,029
)
 
 
$
10,559

 
$
16,115

Contract cost and recognized income not yet billed
 
$
20,451

 
$
30,662

Contract billings in excess of cost and recognized income
 
(9,892
)
 
(14,547
)
 
 
$
10,559

 
$
16,115