Supplemental Cash Flow Information (Tables)

12 Months Ended

Dec. 31, 2018

Supplemental Cash Flow Elements [Abstract]

Supplemental Cash Flow Information

	Year ended December 31,
	2018		2017		2016
Amount paid for interest	$	57,144	$	45,472	$	44,063
Amount paid for income taxes, net	9,261		42,003		132,695
Non-cash conversion of convertible notes to common shares	—		—		43,215
Accrued capital expenditures	$	6,492	$	13,824	$	12,391