Derivative Financial Instruments - Derivative Financial Instruments Narrative (Details)	12 Months Ended
	Dec. 31, 2018 USD ($) contracts counterparty	Dec. 31, 2017 USD ($) counterparty	Dec. 31, 2016 USD ($)	Sep. 30, 2018 USD ($)	Apr. 30, 2018 USD ($)	Dec. 31, 2015 USD ($)
Derivative [Line Items]
Accumulated other comprehensive income (loss), net of tax	$ (196,305,000)	$ (170,478,000)
Long-term debt	637,813,000
Interest rate					1.38%
Secured Debt [Member]
Derivative [Line Items]
Long-term debt	1,037,813,000	619,477,000
Accumulated Other Comprehensive Income, Net Unrealized Gain (Loss) on Nonderivative Instruments [Member]
Derivative [Line Items]
Accumulated other comprehensive income (loss), net of tax	$ (14,380,000)	$ (14,380,000)	$ (14,380,000)			$ (14,380,000)
Number of Counterparties [Member]
Derivative [Line Items]
Number of counterparties | counterparty	5	3
London Interbank Offered Rate (LIBOR) [Member] | Secured Debt [Member]
Derivative [Line Items]
Long-term debt	$ 637,800,000
Interest Rate Swap [Member]
Derivative [Line Items]
Number of interest rate derivatives held	1
Interest rate cash flow hedge gain (loss) to be reclassified during next 12 months	$ 1,900,000
Derivative, notional amount			$ 214,000,000
Derivative, fixed interest rate			1.42%
Interest Rate Cap [Member]
Derivative [Line Items]
Number of interest rate derivatives held	3
Interest rate cash flow hedge gain (loss) to be reclassified during next 12 months				$ 200,000
Derivative, cap interest rate	2.00%		2.00%
Derivative, notional amount	$ 100,000,000		$ 100,000,000
Derivative purchase price			$ 1,700,000
Currency Swap [Member]
Derivative [Line Items]
Derivative, notional amount					$ 56,000,000.0
Foreign currency cash flow hedge gain (loss) to be reclassified during next 12 months					$ 1,600,000
Forward Contracts [Member]
Derivative [Line Items]
Number of instruments held | contracts	57
Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member] | Minimum [Member]
Derivative [Line Items]
Derivative, notional amount	$ 107,000
Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member] | Maximum [Member]
Derivative [Line Items]
Derivative, notional amount	$ 47,500,000