Supplemental Cash Flow Information (in thousands) - Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended			9 Months Ended			12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2013	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Interest and taxes paid:
Interest paid	$ 11,836	$ 129	$ 31	$ 25,222	$ 2,105	$ 2,152	$ 38,614	$ 8,944	$ 2,178	$ 34,404	$ 6,294	$ 27,450
Income taxes paid		$ 1,806	$ 2		$ 16,449					$ 54,763	$ 31,413	$ 4,320