Changes in Stock Appreciation Rights (Detail) (SARs, USD $)	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
SARs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
SARs, Exercised	293,925	[1]	126,624	[1]
Weighted Average Base Price, Exercised	$ 8.07	[1]	$ 7.40	[1]
Weighted Average Fair Value, Exercised	$ 4.70	[1]	$ 4.45	[1]

[1] The exercise of SARs listed in this table resulted in the issuance of 120,459 shares and 37,233 shares of ICG’s Common Stock during the three months ended March 31, 2014 and 2013, respectively.