Leased Assets and Liabilities (Supplemental Cash Flow Information) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Leases [Abstract]
Operating cash outflows - operating leases	$ 11,073	$ 10,987	$ 22,870	$ 22,738
Operating cash outflows - finance leases	176	125	348	243
Financing cash outflows - finance leases	775	592	1,520	1,156
Leased assets obtained in exchange for new lease obligations
Operating leases	40,907	3,998	49,060	6,994
Finance leases	$ 430	$ 88	$ 2,103	$ 1,160