Commitments and contingencies (Tables)

12 Months Ended

Dec. 31, 2018

Commitments and Contingencies Disclosure [Abstract]

Schedule of Future Commitments Under Noncancelable Operating Leases

Approximate annual future commitments under noncancelable operating leases as of December 31, 2018 are as follows:

	Amount
2019	$	15,911
2020	15,219
2021	13,454
2022	12,561
2023	11,133
Thereafter	45,324
Total	$	113,602