Leases (Schedule of Maturity of Lease Liabilities) (Details) - USD ($) $ in Thousands		Sep. 30, 2019	Dec. 31, 2018
Operating Leases
October 1, 2019 to September 30, 2020		$ 60,630
October 1, 2020 to September 30, 2021		49,507
October 1, 2021 to September 30, 2022		40,141
October 1, 2022 to September 30, 2023		33,471
October 1, 2023 to September 30, 2024		24,566
Thereafter		73,298
Total minimum lease payments		281,613
Less: Amount of lease payments representing interest		(36,479)
Present value of future minimum lease payments		245,134
Current portion of lease liabilities		51,632	$ 0
Noncurrent portion of lease liabilities		193,502	0
Finance Leases
October 1, 2019 to September 30, 2020		4,507
October 1, 2020 to September 30, 2021		3,077
October 1, 2021 to September 30, 2022		1,857
October 1, 2022 to September 30, 2023		838
October 1, 2023 to September 30, 2024		164
Thereafter		142
Total minimum lease payments		10,585
Less: Amount of lease payments representing interest		(605)
Present value of future minimum lease payments	[1]	9,980	$ 4,213
Current portion of lease liabilities		4,192
Noncurrent portion of lease liabilities		$ 5,788

[1] See Note 14 - Leases for further disclosure regarding finance lease obligations.