Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Supplemental Cash Flow Information [Abstract]
Interest paid	$ 16,711	$ 9,854
Noncash investing and financing activity
Equity issued in conjunction with acquisition	123,146	0
Capital projects incurred but not yet paid	15,974	7,115
Removal of pre-existing equity method investment	(159,459)	0
Purchase price holdback/ other accrued liabilities	31,518	0
Dividends declared not yet paid	5,527	4,663
Debt resulting from accounting standard adoption	0	36,953
Railcar assets and liabilities resulting from accounting standard adoption	$ 0	$ 25,643