Investments in Unconsolidated Entities Investments Ownership Interest (Details) - Variable Interest Entity, Not Primary Beneficiary - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2017
Main Street WP Hotel Associates, LLC
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage		50.00%	50.00%
FBC-CHI Hotels, LLC
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage		40.00%	40.00%
CS Hotel 30W46th, LLC
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage		25.00%	25.00%
CS Brickell, LLC
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage		50.00%	50.00%
CS Maple Grove, LLC
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage		50.00%	50.00%
CS Hotel West Orange, LLC
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage		50.00%	50.00%
Hotel JV Services, LLC
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage		16.00%	16.00%
City Market Hotel Development, LLC
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage		43.00%	43.00%
CS Woodlands, LLC
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage		50.00%	50.00%
926 James M. Wood Boulevard, LLC
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage		75.00%	75.00%
CS Dallas Elm, LLC
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage		45.00%	45.00%
Choice Hotels Canada, Inc.
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage		50.00%	50.00%
CS 433 Mason LLC
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage		100.00%	90.00%
Consideration transferred	$ 3.2
Pine Street Long Beach LLC
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage		50.00%	50.00%
SY Valley Vineyard Resorts LLC
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage		50.00%	50.00%
CS Lakeside Santa Clara LLC
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage		50.00%	0.00%
CS Main Pleasant Hill LLC
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage		50.00%	0.00%