Supplemental Condensed Consolidated Financial Information (Condensed Consolidating Balance Sheets) (Parenthetical) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Condensed Financial Statements, Captions [Line Items]
Accounts receivable, allowance for doubtful accounts	$ 2,531	$ 2,531
Common stock, shares issued	55,467,987	54,055,600
Consolidating Adjustments [Member]
Condensed Financial Statements, Captions [Line Items]
Accounts receivable, allowance for doubtful accounts	$ 0	$ 0
Common stock, shares issued	0	0
Parent [Member]
Condensed Financial Statements, Captions [Line Items]
Accounts receivable, allowance for doubtful accounts	$ 1,205	$ 1,205
Common stock, shares issued	55,467,987	54,055,600
Combined Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Accounts receivable, allowance for doubtful accounts	$ 1,326	$ 1,326
Common stock, shares issued	0	0
Combined Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Accounts receivable, allowance for doubtful accounts	$ 0	$ 0
Common stock, shares issued	0	0