Related Party Transactions (Details) (USD $)	3 Months Ended		9 Months Ended					9 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 6th & Pine Development, LLC	Sep. 30, 2013 Property Subject to Operating Lease 6th & Pine Development, LLC	Feb. 27, 2013 Property Subject to Operating Lease 6th & Pine Development, LLC property	Sep. 30, 2013 Property Subject to Operating Lease Building A 6th & Pine Development, LLC	Feb. 27, 2013 Property Subject to Operating Lease Building A 6th & Pine Development, LLC sqft	Sep. 30, 2013 Property Subject to Operating Lease Building B 6th & Pine Development, LLC	Feb. 27, 2013 Property Subject to Operating Lease Building B 6th & Pine Development, LLC Option sqft
Related Party Transaction [Line Items]
Number of office buildings leased							2
Number of office building lease that is under construction							1
Area of office and storage space									90,000		120,000
Lease commencement date								Jun. 06, 2013		Nov. 01, 2014
Lease expiration date					Dec. 31, 2024
Number of extension option											2
Additional extension lease term										5 years
Initial annual rental expense								$ 2,600,000		$ 4,000,000
Annual rental increase percentage						0.0375
Payments for medical services fees to related party	$ 8,200,000	$ 7,000,000	$ 24,600,000	$ 20,600,000