Restructuring Charges (Narratives) (Details) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Jun. 30, 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 0	$ 1,900,000	$ 0	$ 1,900,000
Accelerated depreciation of leasehold improvements and fixed assets		1,700,000		1,700,000
Cash payments			2,240,000
Reduction-in-force
Restructuring Cost and Reserve [Line Items]
Severance and benefits charges					$ 5,600,000
Cash payments			$ 2,200,000
Sub Lease Income for Non-cancelable Lease Payments for Excess Facilities
Restructuring Cost and Reserve [Line Items]
Restructuring charges		$ 100,000		$ 100,000