Shareholders' Equity - Narrative (Details) - USD ($)				1 Months Ended		3 Months Ended
	Oct. 23, 2018	Sep. 26, 2018	Mar. 14, 2018	Mar. 31, 2019	Feb. 28, 2019	Mar. 31, 2019	Mar. 31, 2018	Mar. 13, 2019
Class of Stock [Line Items]
Common stock, dividend declared (in dollars per share)		$ 2.5			$ 2.5
Common stock, cash dividends paid	$ 304,700,000				$ 1,200,000
Common Shares
Class of Stock [Line Items]
Shares paid for tax withholding for share based compensation (in shares)						163,913	57,348
Share Repurchase Program, March 14, 2018
Class of Stock [Line Items]
Stock repurchase program, period in force			12 months
Share Repurchase Program, March 14, 2018 | Common Shares
Class of Stock [Line Items]
Stock repurchase program, authorized amount (up to)			$ 150,000,000
Stock repurchase program, amount not utilized				$ 130,900,000
Share Repurchase Program, March 13, 2019 | Common Shares
Class of Stock [Line Items]
Stock repurchase program, additional authorized amount (up to)								$ 150,000,000
Repurchase of shares (in shares)						0
Stock repurchase program, remaining authorized repurchase amount				$ 150,000,000		$ 150,000,000