Geographic Information (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Geographic information [Line Items]
Revenues	$ 282,647	$ 121,301	$ 108,582
Identifiable assets	1,232,664	225,109	217,786
U.S. [Member]
Geographic information [Line Items]
Revenues	228,044	73,388	65,010
Identifiable assets	1,171,540	176,638	170,584
Latin America [Member]
Geographic information [Line Items]
Revenues	40,372	34,556	33,430
Identifiable assets	51,036	38,426	37,611
Canada [Member]
Geographic information [Line Items]
Revenues	6,860	5,549	3,950
Identifiable assets	5,915	6,650	5,942
Other [Member]
Geographic information [Line Items]
Revenues	7,371	7,808	6,192
Identifiable assets	$ 4,173	$ 3,395	$ 3,649