Operating Leases Operating Leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Future Minimum Lease Payments Under Noncancelable Operating Leases [Line Items]
Description of Lessee Leasing Arrangements, Operating Leases	12
Operating Leases, Rent Expense	$ 3,800	$ 3,700	$ 5,100
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Operating Leases, Future Minimum Payments Due	31,533
Operating Leases, Future Minimum Payments Due, Next Twelve Months	4,064
Operating Leases, Future Minimum Payments, Due in Two Years	4,141
Operating Leases, Future Minimum Payments, Due in Three Years	4,185
Operating Leases, Future Minimum Payments, Due in Four Years	4,030
Operating Leases, Future Minimum Payments, Due in Five Years	3,979
Operating Leases, Future Minimum Payments, Due Thereafter	$ 11,134
Office Lease
Future Minimum Lease Payments Under Noncancelable Operating Leases [Line Items]
Lease Expiration Year	2023
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Operating Leases, Future Minimum Payments Due	$ 12,622
Operating Leases, Future Minimum Payments Due, Next Twelve Months	2,097
Operating Leases, Future Minimum Payments, Due in Two Years	2,171
Operating Leases, Future Minimum Payments, Due in Three Years	2,221
Operating Leases, Future Minimum Payments, Due in Four Years	2,062
Operating Leases, Future Minimum Payments, Due in Five Years	2,011
Operating Leases, Future Minimum Payments, Due Thereafter	2,060
Ground Lease
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Operating Leases, Future Minimum Payments Due	18,911
Operating Leases, Future Minimum Payments Due, Next Twelve Months	1,967
Operating Leases, Future Minimum Payments, Due in Two Years	1,970
Operating Leases, Future Minimum Payments, Due in Three Years	1,964
Operating Leases, Future Minimum Payments, Due in Four Years	1,968
Operating Leases, Future Minimum Payments, Due in Five Years	1,968
Operating Leases, Future Minimum Payments, Due Thereafter	$ 9,074
Minimum | Ground Lease
Future Minimum Lease Payments Under Noncancelable Operating Leases [Line Items]
Lease Expiration Year	2017
Maximum | Ground Lease
Future Minimum Lease Payments Under Noncancelable Operating Leases [Line Items]
Lease Expiration Year	2054