- Contractual Obligations and Minimum Rental Receipts (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013
Obligations for tenant improvement allowances and lease inducement costs for lease in place and commitments for buildings [Abstract]
2014	$ 7,805
2015	0
2016	69
2017	0
2018	315
Total	8,189
Minimum future operating lease payments
2014	156
2015	66
2016	32
2017	21
2018	10
Total	285
Future approximate minimum rental receipts under noncancelable leases [Abstract]
2014	267,265
2015	253,249
2016	230,538
2017	193,744
2018	162,430
Thereafter	682,965
Total	1,790,191
Ground Leases, Future Minimum Payments Due [Abstract]
2014	267,265
2015	253,249
2016	230,538
2017	193,744
2018	162,430
Thereafter	682,965
Total	1,790,191
Westshore Corporate Center [Member]
Ground Leases, Future Minimum Payments Due [Abstract]
Remaining lease term	21 years 0 months 0 days
NASCAR Plaza [Member]
Ground Leases, Future Minimum Payments Due [Abstract]
Remaining lease term	92 years 0 months 0 days
Corporate Center Four [Member]
Ground Leases, Future Minimum Payments Due [Abstract]
Remaining lease term	67 years 0 months 0 days
Development rental rate (in dollars per gross floor foot area)	0.40
Period between increases in development rental rate subsequent to fixed rate period	5 years 0 months 0 days
Maximum periodic increase in development rental rate (in percent)	10.00%
Lincoln Place [Member]
Ground Leases, Future Minimum Payments Due [Abstract]
Remaining lease term	39 years
Ground Lease [Member]
Future approximate minimum rental receipts under noncancelable leases [Abstract]
2014	792
2015	872
2016	793
2017	793
2018	794
Thereafter	30,929
Total	34,973
Ground Leases, Future Minimum Payments Due [Abstract]
2014	792
2015	872
2016	793
2017	793
2018	794
Thereafter	30,929
Total	$ 34,973