Commitments and Contingencies (Details) - USD ($)		12 Months Ended
	Aug. 21, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Term of lease		15 years
Minimum monthly lease rental		$ 500,000
Initial term of lease over which minimum lease rent is required to be payable		10 years
Last term of lease		5 years
Rent expense		$ 1,300,000	$ 7,000,000	$ 6,400,000
Future non-cancelable minimum payments under operating leases
2016		4,500
2017		3,700
2018		3,700
2019		1,200
2020		600
Thereafter		2,500
Total minimum lease payments		16,200
Future non-cancelable minimum payments under direct financing
2016		5,400
2017		5,400
2018		5,400
2019		5,400
2020		5,400
Thereafter		52,300
Total minimum lease payments		79,300
Future non-cancelable minimum payments under capital leases
2016		100
Total minimum lease payments		100
Pending Land and Building Acquisition | Agreement of Sale with Augustine Land II, L.P.
Future non-cancelable minimum payments under direct financing
Total minimum lease payments		79,300,000
Contingencies
Purchase price of leased land and office building to be acquired	$ 79,900,000
Deposit with a third party escrow agent	4,000,000
Deposit with seller	$ 4,000,000	$ 8,000,000