Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2017

Commitments and Contingencies Disclosure [Abstract]

Future Minimum Annual Lease Payments under Capital and Operating Leases with Non-cancelable Terms in Excess of One Year

Future minimum annual lease payments under capital and operating leases with noncancelable terms in excess of one year as of December 31, 2017, are as follows (in thousands):

	Capital Leases		Operating Leases
2018	$	2,124	$	35,028
2019	2,165		29,633
2020	2,336		23,443
2021	2,327		16,253
2022	2,070		10,680
Thereafter	14,172		17,114
Total future minimum lease obligation	$	25,194	$	132,151