Note 1 - Summary of Significant Accounting Policies (Detail) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Economic Interest	100.00%
Financing Receivable, Past Due, Term	90 days
Number of Portfolio Segments	1
Restricted Cash and Cash Equivalents (in Dollars)	$ 4.0	$ 5.6
Capitalized Computer Software, Net (in Dollars)	26.8	23.8
Capitalized Computer Software, Amortization (in Dollars)	$ 5.5	$ 3.1	$ 1.9
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in Shares)	11,159,160	13,304,016	12,085,874
Restricted Stock Awards, Method of Calculation, Number of Classes	2
Number of Equity Participation Plans	2
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in Shares)	8,871,495	5,776,270	5,874,704
Number of Amendment Types	2
Number of Statements	2
The Home Depot [Member] | Base Rental Revenue [Member]
Concentration Risk, Percentage	3.00%
TJX Companies [Member] | Base Rental Revenue [Member]
Concentration Risk, Percentage	2.90%
Wal-Mart [Member] | Base Rental Revenue [Member]
Concentration Risk, Percentage	2.60%
Sears Holdings [Member] | Base Rental Revenue [Member]
Concentration Risk, Percentage	2.00%
Bed Bath & Beyond [Member] | Base Rental Revenue [Member]
Concentration Risk, Percentage	1.70%
Prior Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in Shares)	47,000,000
The 2010 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in Shares)	10,000,000
Stock Options [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	5 years
Stock Options [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	3 years
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Expiration Period	10
Restricted Stock [Member] | First Half [Member] | iii [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	3 years
Share-based Compensation Arrangement by Share-based Payment Award, Percent Vested	50.00%
Restricted Stock [Member] | Second Half [Member] | iii [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	2 years
Share-based Compensation Arrangement by Share-based Payment Award, Percent Vested	50.00%
Restricted Stock [Member] | i [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Percent Vested	100.00%
Restricted Stock [Member] | ii [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	4 years
Restricted Stock [Member] | ii [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	3 years
Restricted Stock [Member] | iii [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	3 years
Restricted Stock [Member] | iv [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	10 years
Share-based Compensation Arrangement by Share-based Payment Award, Percent Vested	20.00%
Largest [Member]
Number of Tenants		5
Potential Adjustment [Member]
Number of Years	1
Construction Completion [Member]
Number of Years	1
Cash Equivalents Policy [Member]
Number of Months	3
After Issuance [Member]
Number of Years	1
Base Rental Revenue [Member]
Concentration Risk, Percentage	1.70%
Gross Leasable Area [Member]
Concentration Risk, Percentage	1.20%
Maximum [Member] | Computer Software, Intangible Asset [Member]
Finite-Lived Intangible Asset, Useful Life	5 years
Maximum [Member]
Noncontrolling Interest, Ownership Percentage by Parent		100.00%
Minimum [Member] | Computer Software, Intangible Asset [Member]
Finite-Lived Intangible Asset, Useful Life	3 years