Goodwill - Carrying Amount of Goodwill (Details) - USD ($) $ in Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Changes in the carrying amount of goodwill
Balance at January 1, 2016			$ 256,736		$ 256,736
Goodwill Impairment	$ 0	$ (29,600)	(85,900)	$ 0	(115,483)	$ 0
Sale of assets					(8,620)
Effect of foreign exchange rate changes					1,048
Balance at September 30, 2016	133,681				133,681
International
Changes in the carrying amount of goodwill
Balance at January 1, 2016			123,055		123,055
Goodwill Impairment					(115,483)
Sale of assets					(8,620)
Effect of foreign exchange rate changes					1,048
Balance at September 30, 2016	0				0
North America
Changes in the carrying amount of goodwill
Balance at January 1, 2016			$ 133,681		133,681
Goodwill Impairment					0
Sale of assets					0
Effect of foreign exchange rate changes					0
Balance at September 30, 2016	$ 133,681				$ 133,681