Related Party Transactions - Narrative (Details) $ in Thousands	1 Months Ended		2 Months Ended	12 Months Ended
	Jan. 31, 2018	Dec. 31, 2002 USD ($) Property	Nov. 30, 2004 USD ($) Property	Dec. 31, 2017 USD ($) lease	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Related Party Transaction [Line Items]
Lease term (in years)				15 years
Proceeds from disposition of business, net of cash acquired				$ 1,141	$ 35,899	$ 13,976
Related Party
Related Party Transaction [Line Items]
Number of operating leases | lease				10
Properties sold | Property		10	11
Borrowings collateralized by the land and buildings		$ 5,000	$ 6,800
Lease term (in years)			15 years
Aggregate annual rental		$ 800	$ 800
Subsequent Event | Related Party
Related Party Transaction [Line Items]
Lease term (in years)	5 years
Subsequent Event | Minimum | Related Party
Related Party Transaction [Line Items]
Lease term (in years)	5 years
Subsequent Event | Maximum | Related Party
Related Party Transaction [Line Items]
Lease term (in years)	8 years