Equity Method Investments - The Company's Equity in Earnings (Loss) of Joint Ventures (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Schedule of Equity Method Investments [Line Items]
Equity in earnings (loss) of joint ventures	$ 1,562	$ 1,621	$ 6,010	$ 7,287
ICP [Member]
Schedule of Equity Method Investments [Line Items]
Equity in earnings (loss) of joint ventures	1,562	1,604	6,120	7,192
DMI [Member]
Schedule of Equity Method Investments [Line Items]
Equity in earnings (loss) of joint ventures	$ 0	$ 17	$ (110)	$ 95