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, 2019 and thereafter, are as follows:

Period	Amount
2019	$	58,015
2020	55,211
2021	45,974
2022	40,387
2023	38,348
2024 and thereafter	107,975
	$	345,910