Equity-Based Compensation (Details Textual) (USD $) In Millions, except Share data, unless otherwise specified	9 Months Ended			9 Months Ended	3 Months Ended		9 Months Ended		3 Months Ended			9 Months Ended			3 Months Ended		9 Months Ended			9 Months Ended			9 Months Ended					1 Months Ended	3 Months Ended		9 Months Ended			9 Months Ended		9 Months Ended		9 Months Ended		9 Months Ended		9 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011	Sep. 30, 2012 Executives of a Consolidated Subsidiary [Member]	Sep. 30, 2012 Non-Management Directors (Director Plan) [Member]	Sep. 30, 2011 Non-Management Directors (Director Plan) [Member]	Sep. 30, 2012 Non-Management Directors (Director Plan) [Member]	Sep. 30, 2011 Non-Management Directors (Director Plan) [Member]	Sep. 30, 2011 Non-Management Directors (Director Plan) [Member] Maximum [Member]	Sep. 30, 2012 SARs [Member]	Sep. 30, 2011 SARs [Member]	Sep. 30, 2012 SARs [Member]	Sep. 30, 2011 SARs [Member]	Dec. 31, 2011 SARs [Member]	Sep. 30, 2012 Stock Option [Member]	Sep. 30, 2011 Stock Option [Member]	Sep. 30, 2012 Stock Option [Member]	Sep. 30, 2011 Stock Option [Member]	Dec. 31, 2011 Stock Option [Member]	Sep. 30, 2012 Stock Option [Member] Consolidated Core Companies [Member]	Sep. 30, 2012 Restricted Stock Units (RSUs) [Member]	Dec. 31, 2011 Restricted Stock Units (RSUs) [Member]	Sep. 30, 2012 Restricted Stock Units (RSUs) [Member] Employees [Member]	Sep. 30, 2012 Restricted Stock Units (RSUs) [Member] Executives of a Consolidated Subsidiary [Member]	Sep. 30, 2011 Restricted Stock Units (RSUs) [Member] Executives of a Consolidated Subsidiary [Member]	Sep. 30, 2012 Director Plan [Member] Non-Management Directors (Director Plan) [Member]	Sep. 30, 2011 Director Plan [Member] Non-Management Directors (Director Plan) [Member]	Oct. 31, 2011 Restricted Stock [Member]	Sep. 30, 2012 Restricted Stock [Member]	Sep. 30, 2011 Restricted Stock [Member]	Sep. 30, 2012 Restricted Stock [Member]	Sep. 30, 2011 Restricted Stock [Member]	Sep. 30, 2012 First Vesting [Member] Restricted Stock Units (RSUs) [Member] Employees [Member]	Sep. 30, 2012 First Vesting [Member] Restricted Stock [Member]	Sep. 30, 2012 Second Vesting [Member] Restricted Stock Units (RSUs) [Member] Employees [Member]	Sep. 30, 2012 Second Vesting [Member] Restricted Stock [Member]	Sep. 30, 2012 Third Vesting [Member] Restricted Stock Units (RSUs) [Member]	Sep. 30, 2012 Third Vesting [Member] Restricted Stock [Member]	Sep. 30, 2012 Fourth Vesting [Member] Restricted Stock Units (RSUs) [Member]	Sep. 30, 2012 Fourth Vesting [Member] Restricted Stock [Member]	Sep. 30, 2012 Fifth Vesting [Member] Restricted Stock Units (RSUs) [Member]	Sep. 30, 2012 Fifth Vesting [Member] Restricted Stock [Member]	Sep. 30, 2012 Sixth Vesting [Member] Restricted Stock Units (RSUs) [Member]	Sep. 30, 2012 Sixth Vesting [Member] Restricted Stock [Member]	Sep. 30, 2012 Seventh Vesting [Member] Restricted Stock Units (RSUs) [Member] Subsidiary [Member]
Equity-Based Compensation (Additional Textual) [Abstract]
SARs vesting period	4 years											4 years					36 months
SARs, Exercised										16,000		16,000	98,057
Forfeited of SARs												1,598
SARs outstanding	1,516									4,389,311	19,998	4,389,311	19,998	4,147,391
Stock options, exercised															26,342	15,300	56,842	18,725
Stock options, expired															229	39,619	8,229	108,736
Stock options, forfeited																	21
Stock options, outstanding															118,116		118,116		183,208
Aggregate intrinsic value of the stock options, outstanding															$ 0.6		$ 0.6		$ 0.3
Restricted stock awards Granted																															116,973	81,910
Restricted stock awards vesting period																							4 years	7 years
Restricted stock awards vesting period one year																	1 year
Remaining Restricted stock awards vesting equally each six months																							87.50%
Restricted stock awards Vested	52,500	39,000																													68,711	6,250
Restricted stock awards vesting on the Nine month anniversary																							12.50%
Restricted stock issued and unvested																					1,273,672	1,225,785
Restricted stock awards vesting rate																							25.00%
Restricted stock awards vesting on anniversary				100.00%
Restricted stock awards vesting description				100% on the one-year anniversary date of the grant or upon the achievement of certain performance conditions or 100% on the seven-year anniversary of the grant
Restricted stock awards vesting amortization																								0.1	0.3
Restricted stock awards expenses																								0.1	0.3
Deferred Stock Units vesting period							1 year
Deferred Stock Units, issued under director plan					9,473	2,759	24,724	8,493																		41,250	52,500
Deferred Stock Units unvested							41,250	52,500
Deferred Stock Units expense					0.1		0.3	0.1	0.1
Stock Options vesting period	4 years											4 years					36 months
Equity-based compensation awards vesting on the first anniversary																	25.00%			25.00%
Remaining Equity-based compensation awards vesting equally each month																	75.00%			75.00%
Remaining awards vesting period																	25.00%
Restricted stock issued to chief executive officers																												1,100,000
Restricted Stock Awards Vesting Shares																																	87,498		69,875		320,834		366,666		366,666		18,750		43,383
Restricted stock vesting description																															43,383 shares of restricted stock relate to awards issued to executives of one of its consolidated subsidiaries and vest upon the achievement of certain performance conditions or the seven-year anniversary of the grant			87,498 shares of restricted stock vest 25% each year over a four-year period		69,875 shares of restricted stock vest 12.5% on the nine-month anniversary of the grant date, and the remaining 87.5% every six months subsequent to the first vesting date		320,834 shares of restricted stock vest in equal installments each November and May through November 9, 2015		366,666 shares of restricted stock vest based on certain performance goals related to ICG’s results		366,666 shares of restricted stock vest based on stipulated market thresholds related to ICG’s Common Stock price through December 31, 2015		18,750 shares of restricted stock vest 100% on the one-year anniversary date of the grant
Equity-Based Compensation (Textual) [Abstract]
SARs vesting on the first anniversary	25.00%
Remaining SARs vesting equally each month	75.00%
Subsequent vesting of remaining SARs, period	36 months
Aggregate intrinsic values of the SARs outstanding	$ 11.1		$ 2.1