Equity Method Investments (Detail) - The Company's Investment in Joint Ventures (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014		Dec. 31, 2013
Schedule of Equity Method Investments [Line Items]
Equity Method Investments	$ 14,364		$ 7,123
ICP [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments	13,845	[1]	6,653	[1]
DMI [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments	$ 519		$ 470

[1] The cumulative effect of the change in estimate was a decrease in equity interest in ICP of $1,882, which effectively reduced the Company's investment in ICP from 30 percent to 26.4 percent at September 30, 2014.