Commitments (Tables)

12 Months Ended

Dec. 31, 2017

Commitments [Abstract]

Schedule of Minimum Lease Payments

At December 31, 2017, future minimum annual lease payments under all noncancelable leases are as follows:

2018	$	72,148
2019	57,776
2020	45,466
2021	30,925
2022	19,024
Thereafter	34,556
	$	259,895