Share-Based and Long-Term Compensation Plans (Details) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized for issuance (in shares)	600,000
Term of equity plan	10 years 0 months 0 days
Vesting period	4 years 0 months 0 days
Period of performance goals	3 years 0 months 0 days
Share-based compensation expense	$ 89,000	$ 157,000
Nonvested awards total compensation expense not yet recognized	724,000
Maximum number of shares granted for stock options or stock appreciation rights	2,000,000
Number of shares available for awards	3,250,000
Maximum number of shares granted pursuant to other awards	1,250,000
Nonvested awards, period over which expense will be recognized	1 year 6 months 0 days
Weighted Average Grant-Date Fair Value [Roll Forward]
Stock options granted	1,850,000
LTIP Units Issued	114,443
Restricted stock units issued	173,947
Time vesting restricted stock units issued	115,350
Performance vesting restricted stock units issued	58,597
Restricted Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Target absolute return goal (in hundredths)	12.00%
Threshold relative return goal	RMS + 100 bps
Target relative return goal	RMS + 200 bps
Maximum relative return goal	RMS + 300 bps
Threshold absolute goal award earnings (in hundredths)	15.00%
Target absolute goal award earnings (in hundredths)	60.00%
Threshold relative goal award earnings (in hundredths)	20.00%
Target relative goal award earnings (in hundredths)	55.00%
Maximum absolute goal award earnings (in hundredths)	100.00%
Maximum relative goal award earnings (in hundredths)	100.00%
Annual performance achievement vesting percentage (in hundredths)	50.00%
Fair value of incentive awards at period end	2,000,000
Restricted shares and deferred incentive share unit activity [Roll Forward]
Balance at beginning of period (in shares)	281,233,000
Vested (in shares)	(11,786,000)
Forfeited (in shares)	(24,975,000)
Balance at end of period (in shares)	244,472,000
Weighted Average Grant-Date Fair Value [Roll Forward]
Balance at beginning of period (in dollars per share)	$ 8.34
Vested (in dollars per share)	$ 15.14
Forfeited (in dollars per share)	$ 7.53
Balance at end of period (in dollars per share)	$ 8.09
Restricted Shares [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum absolute return goal (in hundredths)	14.00%
Restricted Shares [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Threshold absolute return goal (in hundredths)	10.00%
Deferred Incentive Share Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of incentive awards at period end	356,000
Restricted shares and deferred incentive share unit activity [Roll Forward]
Balance at beginning of period (in shares)	17,760,000
Vested (in shares)	0
Forfeited (in shares)	(525,000)
Balance at end of period (in shares)	17,235,000
Weighted Average Grant-Date Fair Value [Roll Forward]
Balance at beginning of period (in dollars per share)	$ 25.61
Vested (in dollars per share)	$ 0
Balance at end of period (in dollars per share)	$ 20.66
Long-term Cash Incentive [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Absolute compounded annual TRS threshold for achievement of performance goals, first condition (in hundredths)	(i) achieve an absolute compounded annual TRTS that exceeds 14% and (ii) achieve an absolute compounded annual TRTS that exceeds the compounded annual return of the RMS by at least 500 basis points
Absolute compounded annual TRS threshold for achievement of performance goals, second condition	achieve an absolute compounded annual TRTS that exceeds the compounded annual return of the RMS by at least 600 basis points
Aggregate cash incentive earned, maximum	$ 7,100,000
Absolute compounded annual TRS goal (in hundredths)	23.00%