Income Taxes - Provision and Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current:
Federal	$ 0	$ 0	$ (5,431)
State	2,327	1,575	1,713
Foreign	593	667	670
Current tax	2,920	2,242	(3,048)
Deferred:
Foreign	(127)	(1,047)	(236)
Deferred tax	(127)	(1,047)	(236)
Income tax provision (benefit)	$ 2,793	$ 1,195	(3,284)
Tax Cuts and Jobs Act of 2017, provisional income tax benefit			$ 5,431
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Taxes at statutory U.S. federal income tax rate	21.00%	21.00%	35.00%
Nontaxable income of SVC	(21.00%)	(21.00%)	(35.00%)
Minimum tax credit refund	(0.00%)	(0.00%)	(2.60%)
State and local income taxes, net of federal tax benefit	0.70%	0.80%	0.80%
Foreign taxes	0.10%	(0.20%)	0.20%
Tax Act adjustment	0.000	0.000	0.218
Change in valuation allowance	0.00%	0.00%	(21.80%)
Other differences, net	0.00%	0.00%	0.00%
Effective tax rate	0.80%	0.60%	(1.60%)