Equity Method Investments (Detail) - The Company’s Equity in Earnings (Loss) of Joint Ventures - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Schedule of Equity Method Investments [Line Items]
Equity in earnings (loss) of joint ventures	$ 3,096	$ 2,331	$ 4,448	$ 5,666
ICP [Member]
Schedule of Equity Method Investments [Line Items]
Equity in earnings (loss) of joint ventures	3,229	2,341	4,558	5,588
DMI [Member]
Schedule of Equity Method Investments [Line Items]
Equity in earnings (loss) of joint ventures	$ (133)	$ (10)	$ (110)	$ 78