Leases - Additional Information (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($) Option	Mar. 31, 2018 USD ($)
Lessee Lease Description [Line Items]
Rent expense under ASC 840		$ 2.4
Real Estate and Equipment
Lessee Lease Description [Line Items]
Lease renewal term, operating lease	20 years
Description of option to extend the lease	Many of the Company’s leases include options to extend the leases on a month to month basis or for set periods for up to 20 years.
Operating lease, existense of option to extend	true
Description of option to terminate the lease	Many leases also include options to terminate the leases within 1 year or per other contractual terms.
Lessee, operating lease, existence of option to terminate	true
Real Estate and Equipment | Minimum
Lessee Lease Description [Line Items]
Remaining lease term, operating lease	1 year
Real Estate and Equipment | Maximum
Lessee Lease Description [Line Items]
Remaining lease term, operating lease	20 years
Operating lease, options to terminate lease term	1 year
Corporate Offices
Lessee Lease Description [Line Items]
Initial term of operating lease not yet commenced	20 years
Lease not yet commenced, option to extend	true
Lease not yet commenced, option to extend description	renewal option for two 10-year terms at prevailing market rates
Operating lease not yet commenced, renewal term	10 years
Operating lease not yet commenced, number of renewal option | Option	2
Operating lease not yet commenced, future payments	$ 124.0