Supplemental Cash Flow Information - Supplemental Cash Flow Disclosure (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Interest paid	$ 15,620	$ 13,436	$ 7,244
Income taxes paid	$ 1,100	14,984	$ 455
Computer software
Finite-Lived Intangible Assets [Line Items]
Intangible software assets acquired		$ 7,100