Changes in Accumulated Other Comprehensive Income (Loss) - Summary (Details) - USD ($) $ in Thousands	5 Months Ended	9 Months Ended
	May 31, 2019	Sep. 30, 2019	Sep. 30, 2018
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period	$ 369,275	$ 369,275	$ 353,396
Other comprehensive income (loss)		(8,570)	(9,173)
Amounts reclassified from accumulated other comprehensive loss		19,395	595
Balance at end of period		381,671	377,049
Loss reclassified from AOCI for defined benefit pension plans	400	19,000	600
Tax benefit reclassified from AOCI for defined benefit pension plans	100	11,500	200
Total Accumulated Other Comprehensive (Loss) Income
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period	(42,685)	(42,685)	(20,148)
Balance at end of period		(31,860)	(28,726)
Foreign Currency Translation Adjustment
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period	(18,458)	(18,458)	(2,221)
Other comprehensive income (loss)		(6,396)	(9,262)
Amounts reclassified from accumulated other comprehensive loss		0	0
Balance at end of period		(24,854)	(11,483)
Defined Benefit Pension Adjustment
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period	(22,253)	(22,253)	(18,049)
Other comprehensive income (loss)		0	0
Amounts reclassified from accumulated other comprehensive loss		19,395	595
Balance at end of period		(2,858)	(17,454)
Gains and Losses on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period	$ (1,974)	(1,974)	122
Other comprehensive income (loss)		(2,174)	89
Amounts reclassified from accumulated other comprehensive loss		0	0
Balance at end of period		$ (4,148)	$ 211