Leases - Additional Information (Details)	12 Months Ended
	Dec. 31, 2017 USD ($) lease	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Leases [Abstract]
Letters of credit outstanding, amount related to leases	$ 5,492,000
Leases expiring with no renewal options, next 5 years | lease	25
Leases expiring with no renewal options, current year | lease	8
Leases expiring with renewal options, next 5 years | lease	61
Rent expense excluding deferred lease liabilities	$ 126,318,000	$ 124,952,000	$ 124,920,000
Non-base rent expense	24,881,000	25,384,000	24,767,000
Rent expense	124,997,000	124,333,000	123,872,000
Rental income	2,558,000	2,338,000	4,669,000
Rental income above base rent	$ 0	0	$ 0
Rental income from owned property		$ 1,926,000