Summary of Significant Accounting Policies (Tables)

6 Months Ended

Jun. 30, 2018

Accounting Policies [Abstract]

Schedule of Reconciliation of Cash, Cash Equivalents, and Restricted Cash

The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the statement of financial position that sum to the total of the same such amounts shown in the statement of cash flows:

(in thousands)	June 30, 2018		June 30, 2017
Cash and cash equivalents	$	22,460	$	135,501
Restricted cash in prepaid expenses and other current assets		192		—
Restricted cash (short term)		—		102
Restricted cash (long term)		584		60,682
Total cash, cash equivalents and restricted cash shown in the condensed consolidated    statement of cash flows	$	23,236	$	196,285