Leases (Lease Assets and Liabilities) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Finance lease cost:
Amortization of right-of-use assets	$ 117	$ 693
Interest on lease liabilities	27	113
Operating lease cost	390	308
Short-term lease cost	218	129
Variable lease cost	0	95
Sublease income	0	(1,198)
Total lease cost	752	140
Capitalized operating lease cost	0	3,335
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows for finance leases	(27)	(113)
Operating cash flows for operating leases	(345)	(308)
Investing cash flows for operating leases	0	(1,023)
Financing cash flows for finance leases	(105)	(699)
Right-of-use assets obtained in exchange for new finance lease liabilities	$ 0	$ 670
Operating lease cost, drilling rigs, minimum term	30 days