Schedule II Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Allowance for Doubtful Accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Year	$ 22,015	$ 18,050	$ 18,894
Charged to Cost and Expense	11,295	10,641	5,946
Reductions	(5,588)	(6,039)	(5,665)
Other	11,510	(637)	(1,125)
Balance at End of Year	39,232	22,015	18,050
Deferred Tax Valuation Allowance [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Year	289,642	171,365	141,252
Additions	0	118,277	30,113
Reductions	(50,974)	0	0
Other	0	0	0
Balance at End of Year	238,668	289,642	171,365
LIFO Reserve [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Year	29,625	35,835	50,769
Charged to Cost and Expense	2,884	686	221
Reductions	(4,382)	(6,896)	(15,155)
Other	0	0	0
Balance at End of Year	$ 28,127	$ 29,625	$ 35,835