Equity Method Investments (Detail) (USD $)	0 Months Ended		3 Months Ended		9 Months Ended		0 Months Ended	9 Months Ended				0 Months Ended
	Apr. 19, 2012	Feb. 01, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Apr. 19, 2012 ICP Holdings [Member]	Sep. 30, 2013 ICP Limited Liability Company [Member]	Sep. 30, 2013 ICP [Member]	Feb. 01, 2012 ICP [Member] board_member	Jan. 30, 2012 ICP [Member]	Feb. 01, 2012 ICP [Member] ICP Holdings [Member] board_member	Nov. 20, 2009 ICP [Member] ICP Holdings [Member]	Sep. 30, 2013 DMI [Member]
Schedule of Equity Method Investments [Line Items]
Equity method ownership percentage (percent)									30.00%		50.00%			50.00%
Ownership percentage sold (percent)													50.00%
Option to purchase additional interest (percent)		20.00%
Proceeds from sale of joint venture interest		$ 9,103,000			$ 0	$ 9,103,000
Equity method investee, cumulative percentage ownership by parent (percent)												70.00%
Number of board members entitled to be named (board members)										2		4
Number of board members (board members)										6
EBITDA								500,000
Right to end operations, 3 quarter aggregate EBITDA losses threshold amount								1,500,000
Net working capital								2,500,000
Profit allocation percentage (percent)	30.00%						70.00%
Summarized financial information related party transaction amounts of transaction			$ 110,000	$ 9,697,000	$ 3,510,000	$ 40,331,000