Share-based Compensation-Additional Information (Details) (USD $)	12 Months Ended												12 Months Ended															12 Months Ended						12 Months Ended	3 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Stock options	Dec. 31, 2012 Stock options	Dec. 31, 2011 Stock options	Dec. 31, 2013 Stock options Minimum	Dec. 31, 2013 Stock options Maximum	Dec. 31, 2013 Restricted Stock Awards	Dec. 31, 2012 Restricted Stock Awards	Dec. 31, 2011 Restricted Stock Awards	Dec. 31, 2010 Restricted Stock Awards	Dec. 31, 2013 LTIP units	Dec. 31, 2012 LTIP units	Dec. 31, 2011 LTIP units	Dec. 31, 2013 Performance Shares	Dec. 31, 2012 Performance Shares	Dec. 31, 2011 Performance Shares	Dec. 31, 2013 2010 Notional Unit Long-Term Compensation Plan	Dec. 31, 2012 2010 Notional Unit Long-Term Compensation Plan	Dec. 31, 2011 2010 Notional Unit Long-Term Compensation Plan	Dec. 11, 2013 2010 Notional Unit Long-Term Compensation Plan	Dec. 17, 2012 2010 Notional Unit Long-Term Compensation Plan	Dec. 31, 2010 2010 Notional Unit Long-Term Compensation Plan	Dec. 31, 2013 2010 Notional Unit Long-Term Compensation Plan Minimum	Dec. 31, 2013 2010 Notional Unit Long-Term Compensation Plan Maximum	Dec. 31, 2013 Third Amendment and Restated 2005 Stock Option and Incentive Plan fungibleunits	Dec. 31, 2013 Stock options, stock appreciation rights and other awards fungibleunits	Dec. 31, 2013 All other awards fungibleunits	Dec. 31, 2013 2011 Outperformance Plan	Dec. 31, 2012 2011 Outperformance Plan	Dec. 31, 2011 2011 Outperformance Plan	Aug. 31, 2011 2011 Outperformance Plan	Dec. 31, 2013 Deferred Stock Compensation Plan for Directors	Mar. 31, 2013 Employee Stock Purchase Plan	Dec. 31, 2013 Employee Stock Purchase Plan	Jan. 31, 2008 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum fungible units that may be granted (in shares)																											17,130,000
Fungible units per share (fungible units)																											2.76	0.77	1.0
Award expiration period							5 years	10 years																				5 years	10 years
Shares that may be issued if equal to fungible units (shares)																											17,130,000
Share-based Compensation Arrangement By Share-based Payment Award, Number Of Fungible Units Available For Grant																											4,200,000
Options vesting period							1 year	5 years
Period of commencement of option vesting, from date of grant				1 year
Exercise price of options granted, low end of the range (in dollars per share)				$ 20.67
Exercise price of options granted, high end of the range (in dollars per share)				$ 137.18
Remaining weighted average contractual life of the options outstanding				4 years 7 months 6 days
Remaining weighted average contractual life of the options exercisable				3 years 9 months 28 days
Compensation expense				$ 6,500,000	$ 5,100,000	$ 4,700,000			$ 6,713,155	$ 6,930,381	$ 17,365,401								$ 4,500,000	$ 10,700,000	$ 9,300,000									$ 8,000,000	$ 5,500,000	$ 100,000
Total unrecognized compensation cost related to unvested stock awards				20,300,000					17,800,000							5,000,000
Weighted average period for recognition of compensation cost related to unvested stock awards				3 years					2 years 8 months							1 year 6 months
Share-based Compensation																27,300,000	12,600,000	8,500,000
Annual award vesting rate, low end of range (as a percent)									15.00%
Annual award vesting rate, high end of range (as a percent)									35.00%
Fair value of restricted stock vested during the period									1,600,000	22,400,000	4,300,000
Cost of the plan, subject to adjustment for forfeitures	4,500,000	4,100,000	3,400,000																31,700,000											26,300,000
Weighted average fair value of options granted during the year				18,041,576	6,602,967	4,647,554			17,386,949	7,023,942	21,768,084		27,100,000.0	0	8,500,000
Approximate amount of LTIP units that may be earned by the recipients based on stock price appreciation																									15,000,000	75,000,000							85,000,000
Approximate amount of awards that may be earned by recipients after beginning of the second year if maximum performance achieved																			25,000,000
Approximate amount of awards that may be earned by recipients after beginning of the third year if maximum performance achieved																			25,000,000
Minimum stock price appreciation to earn maximum amount of awards (as a percent)																			50.00%
LTIP units earned (in shares)																				327,416	385,583			366,815
Percentage of LTIP Units earned, vested on December 17, 2012 (percent)																						25.00%	50.00%
Value of LTIP Units that could be earned expressed as percentage of outperformance amount in excess of the 30% benchmark (percent)																																	10.00%
Duration period return to stockholders exceeds 25%																														3 years
Cumulative return to stockholders (percent)																														25.00%
Return to stockholders																														$ 85,000,000.0
Portion of earned LTIP Units vested																														one-third
Percentage of LTIP Units earned, vesting on August 31, 2014 (percent)																														50.00%
Percentage of LTIP Units earned, vesting on August 31, 2015 (percent)																														50.00%
Maximum percentage of the annual retainer fee, chairman fees and meeting fees that may be deferred by non-employee directors (percent)																																		100.00%
Awards granted (in shares)									192,563	92,729	185,333																							7,622
Phantom stock units outstanding (in shares)									2,994,197	2,804,901	2,912,456	2,728,290																						73,524
Shares of common stock available for issuance (shares)																																					500,000
Duration of each offering period starting the first day of each calendar quarter																																			3 months
Purchase price as a percentage of market value of the common stock (percent)																																				85.00%
Shares of common stock issued (shares)																																				73,635