Leases (Tables)

12 Months Ended

Dec. 31, 2017

Leases [Abstract]

Schedule of future minimum lease payments and sublease income

Future minimum lease payments and sublease income at December 31, 2017, by year and in the aggregate, under all noncancellable operating leases and subleases are as follows:

	Lease Payments		Sublease Income
2018	$	201,905	$	121
2019	185,498		81
2020	172,386		—
2021	158,789		—
2022	146,960		—
Thereafter	632,169		—
Total	$	1,497,707	$	202