Basis of Presentation and Significant Accounting Policies (Tables)

6 Months Ended

Jun. 30, 2018

Accounting Policies [Abstract]

Reconciliation of Cash, cash equivalents, and restricted cash equivalents

Reconciliation of cash, cash equivalents, and restricted cash equivalents

(in thousands)	June 30, 2018		December 31, 2017		June 30, 2017		December 31, 2016
Cash and cash equivalents	$	179,507	$	170,345	$	158,577	$	164,313
Restricted cash equivalents	39,809		32,531		5,322		1,142
Total cash, cash equivalents, and restricted cash  equivalents shown in the statement of cash flows	$	219,316	$	202,876	$	163,899	$	165,455