Schedule II—Valuation and Qualifying Accounts

12 Months Ended

Dec. 31, 2017

Valuation and Qualifying Accounts [Abstract]

Schedule II—Valuation and Qualifying Accounts

Schedule II—Valuation and Qualifying Accounts

Description	Balance at beginning of period	Charges to costs and expenses	Recoveries and write offs		Balance at end of period
	(In thousands)
Allowance for doubtful trade receivables
December 31, 2017	5,570	1,709	(2,760	)	4,519
December 31, 2016	7,739	1,259	(3,428	)	5,570
December 31, 2015	6,241	5,741	(4,243	)	7,739
Allowance for excess and slow moving inventory
December 31, 2017	45,648	32,204	5,714		83,566
December 31, 2016	39,247	5,748	653		45,648
December 31, 2015	34,607	8,512	(3,872	)	39,247