Other Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Sep. 30, 2015
Other assets, net
Property and equipment, net	$ 1,341	$ 2,127
Land held for development	188	188
Intangibles, net		6,677
Deferred expense on straightlined third-party tenant leases	3,336	1,426
Interest rate derivative agreements	760
Other receivables	2,201	2,094
Other	1,570	1,973
Total other assets, net	9,396	14,485
Amortization expense	6,479	7,543	$ 10,115
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] | BuyEfficient, LLC
Other assets, net
Intangibles, net		6,700
Intangible assets written off due to sale of asset				$ 6,200
Accumulated amortization		2,400
Amortization expense	$ 400	$ 600	$ 600
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] | BuyEfficient, LLC | Minimum
Other assets, net
Useful life of intangibles		7 years
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] | BuyEfficient, LLC | Maximum
Other assets, net
Useful life of intangibles		20 years