Commitments, Contingencies and Guarantees (Tables)

12 Months Ended

Dec. 31, 2017

Commitments and Contingencies Disclosure [Abstract]

Schedule of Future Minimum Rental Payments for Operating Leases

Minimum rental commitments for the rental of office and production premises and equipment under non-cancellable leases net of sublease income, some of which provide for rental adjustments due to increased property taxes and operating costs, for the years ending December 31, 2018 and thereafter, are as follows:

Period	Amount
2018	$	58,172
2019	56,751
2020	55,065
2021	41,830
2022	32,595
2023 and thereafter	122,947
	$	367,360