Supplemental cash flow information (Tables)

6 Months Ended

Jun. 30, 2016

Supplemental Cash Flow Elements [Abstract]

Supplemental cash flow information

	Six months ended June 30,
	2016		2015
Cash paid for:
Interest	$	9,701	$	9,388
Income taxes	6,316		12,581
Non-cash investing activities:
Accrued capital costs	$	179	$	2,570