Real Estate - Commitments (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013 properties
Commitments and Contingencies Disclosure [Abstract]
Real estate investment, number of properties	47
Real estate held-for-sale, number of properties	2
Real estate, number of properties	49
Real estate investment, funding commitments	$ 148,662	[1]
Real estate held-for-sale, funding commitments	1,662	[1]
Real estate, funding commitments	150,324	[1]
Real estate investment, amount funded	112,387
Real estate held-for-sale, amount funded	947
Real estate, amount funded	113,334
Real estate investment, remaining commitment	36,275
Real estate held-for-sale, remaining commitment	715
Real estate, remaining commitment	$ 36,990

[1] Includes land, construction costs and tenant improvements.