Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2018

Commitments and Contingencies Disclosure [Abstract]

Schedule of contractual obligation, five years [Table Text Block]

The annual minimum payments for the next five years and total minimum payments thereafter are presented below:

Years Ending December 31,	Amount (in thousands)
2019	$	132,502
2020	103,169
2021	88,785
2022	70,741
2023	37,334
Thereafter	24,931
Total	$	457,462