Schedule III - Real Estate and Accumulated Depreciation (Changes in Real Estate Rollforward) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2011
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Balance at the beginning of period	$ 296.8		$ 121.3	$ 86.7
Additions during the period:
Improvements	8.9		1.8	3.4
Acquisitions	391.4		193.7	38.8
Deductions during the period:
Dispositions	(12.5)		(20.0)	(7.6)
Balance at close of period	$ 684.6	[1]	$ 296.8	$ 121.3

[1] (Dollars in millions) Initial Cost Costs Capitalized Subsequent to Acquisition Gross Balance at December 31, 2013 (1) Description Region Encumbrances Land Building & Improvements Improvements Land Building & Improvements Total Accumulated Depreciation Depreciable Life in Years Date of Construction Date Acquired Residential Condominium units Western U.S. 28.0 9.8 95.3 — 9.8 95.3 105.1 (0.2) 39 yrs 2006 2013 Condominium units Western U.S. — — 2.3 — — 0.6 0.6 — 39 yrs 2007 2010 Single family home Western U.S. — 4.1 4.2 0.4 4.5 4.3 8.8 (0.6) 39 yrs 2008 2008 Land 18 acres Western U.S. 1.6 2.3 — — 2.3 — 2.3 — N/A N/A 2011 Single family home lot Western U.S. — 4.1 — 0.3 4.4 — 4.4 — N/A N/A 2010 2700 acres Western U.S. — 31.8 3.8 4.5 35.6 4.3 39.9 (0.6) N/A 1912 2010Grand Total $401.8 $183.2 $489.7 $15.5 $187.8 $496.8 $684.6 $(15.8)