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Defined Contribution Plans (Details)
12 Months Ended
Dec. 31, 2016
USD ($)
employee
Dec. 31, 2015
USD ($)
employee
Dec. 31, 2014
USD ($)
employee
Defined Contribution Plan Disclosure [Line Items]      
Employer matching contribution, percentage of employees' pay 4.00%    
Defined Contribution Plan, contributions paid $ 11,400,000 $ 10,100,000 $ 13,600,000
Multiemployer Defined Contributory Trust Plan [Member]      
Defined Contributory Trust [Abstract]      
Number of employees in plan | employee 1,369 1,431 1,378
Required employer's contribution per hour per active employee $ 0.80 $ 0.75 $ 0.50
Required defined contributory trust contribution, percent of earnings 4.00% 4.00% 4.00%
Period Contributions $ 2,800,000 $ 2,800,000 $ 2,100,000
Defined Contribution Savings Plan [Member] | Minimum [Member]      
Defined Contribution Plan Disclosure [Line Items]      
Percentage Contributed for Additional Performance Target     1.00%
Defined Contribution Savings Plan [Member] | Maximum [Member]      
Defined Contribution Plan Disclosure [Line Items]      
Percentage Contributed for Additional Performance Target     2.00%