Leases - Additional Disclosure (Details) $ in Thousands	1 Months Ended	2 Months Ended	3 Months Ended	12 Months Ended
	Dec. 31, 2014 USD ($) extension_option	Nov. 15, 2017	Mar. 31, 2015 USD ($)	Sep. 30, 2017 USD ($)
Operating Leased Assets [Line Items]
Estimated minimum future rental payments				$ 255,108
Estimated future minimum sublease payments				18,445
Corporate Office Lease
Operating Leased Assets [Line Items]
Initial term of lease, in years	13 years
Annual rent at lease inception	$ 3,000
Annual rent in the terminal year of lease	$ 4,600
Number of extension options | extension_option	2
Renewable term of lease, in years	5 years
Estimated minimum future rental payments				48,200
Estimated future minimum sublease payments				$ 12,200
Regional Offices Sublease | Miami and Mexico City
Operating Leased Assets [Line Items]
Estimated future minimum sublease payments			$ 6,700
Regional Offices Sublease | Miami
Operating Leased Assets [Line Items]
Sublease term			9 years
Regional Offices Sublease | Mexico City
Operating Leased Assets [Line Items]
Sublease term			3 years
Minimum
Operating Leased Assets [Line Items]
Initial term of lease, in years				3 years
Renewable term of lease, in years				3 years
Maximum
Operating Leased Assets [Line Items]
Initial term of lease, in years				10 years
Renewable term of lease, in years				5 years
Subsequent event | Corporate Office Lease
Operating Leased Assets [Line Items]
Initial leased premises surrendered		15.00%
Percent of operating Lease obligation covered by sublease revenue		88.00%