Pension and Postretirement Benefits (Details Textual) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($) plan	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan expense	$ 20,400	$ 18,700	$ 17,700
Postretirement Medical Benefits
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.27%	4.20%	3.48%
Company contributions	$ 2,900	$ 3,200	$ 2,500
Assumed rate of increase in medical costs	7.50%	7.00%	7.00%
Minimum medical cost rate to be acheived	5.00%
United States | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.41%	4.34%	3.63%
Long-term rate of return on assets	6.00%	6.00%	6.00%
MP Improvement Scale Rate (as a percent)	75.00%
Prior service cost to be amortized from accumulated other comprehensive loss next year	$ 200
Estimated net gain (loss) to be amortized from accumulated other comprehensive loss next year	(6,600)
Company contributions	20,552	$ 23,263
United States | Pension Plan | Minimum
Defined Benefit Plan Disclosure [Line Items]
Estimated contributions in the next year	$ 20,000
United States | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Plan assets, target allocation (as a percent)	43.00%
United States | Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Plan assets, target allocation (as a percent)	57.00%
United States | Fixed Income | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Plan assets, target allocation (as a percent)	57.00%	57.00%
Plan assets, actual allocation (as a percent)	59.00%	56.00%
Foreign Plan
Defined Benefit Plan Disclosure [Line Items]
Discount rate			2.25%
Long-term rate of return on assets			3.88%
Foreign Plan | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Discount rate	1.61%	2.42%
Long-term rate of return on assets	3.37%	3.62%
Prior service cost to be amortized from accumulated other comprehensive loss next year	$ 300
Estimated net gain (loss) to be amortized from accumulated other comprehensive loss next year	(4,300)
Company contributions	16,782	$ 21,696
Estimated contributions in the next year	$ 2,000
Number of plans Non-US Assets | plan	2
Foreign Plan | Fixed Income | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Plan assets, target allocation (as a percent)	50.00%	54.00%
Plan assets, actual allocation (as a percent)	50.00%	54.00%
Foreign Plan | U.K. , the Netherlands and Canadian Plan Assets | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Plan assets, actual allocation (as a percent)	94.00%