Stockholders' Equity Repurchases of Common Stock (Details) - USD ($) shares in Thousands, $ in Thousands	1 Months Ended	6 Months Ended
	Jul. 31, 2019	Jun. 30, 2019	Jul. 01, 2018	Feb. 28, 2019	Nov. 30, 2018	Feb. 28, 2018	Feb. 28, 2017
Subsequent Event
Equity, Class of Treasury Stock
Treasury Stock, Shares, Acquired	521
Treasury Stock, Value, Acquired, Cost Method, excluding Commissions	$ 9,980
Stock Repurchase Program, Cost Incurred	$ 7
February 2019 Share Repurchase Program
Equity, Class of Treasury Stock
Stock Repurchase Program, Authorized Amount				$ 225,000
Stock Repurchase Program, Remaining Authorized Repurchase Amount		$ 196,736
November 2018 and February 2019 Share Repurchase Programs
Equity, Class of Treasury Stock
Treasury Stock, Shares, Acquired		2,824
Treasury Stock, Value, Acquired, Cost Method, excluding Commissions		$ 49,721
Stock Repurchase Program, Repurchase Accrual		807
Stock Repurchase Program, Cost Incurred		$ 40
February 2018 Share Repurchase Program
Equity, Class of Treasury Stock
Stock Repurchase Program, Authorized Amount						$ 175,000
Treasury Stock, Shares, Acquired			3,675
Treasury Stock, Value, Acquired, Cost Method, excluding Commissions			$ 62,490
Stock Repurchase Program, Repurchase Accrual			2,146
Stock Repurchase Program, Cost Incurred			$ 52
November 2018 Share Repurchase Program
Equity, Class of Treasury Stock
Stock Repurchase Program, Authorized Amount					$ 220,000
February 2017 Share Repurchase Program
Equity, Class of Treasury Stock
Stock Repurchase Program, Authorized Amount							$ 150,000
Treasury Stock, Shares, Acquired			1,385
Treasury Stock, Value, Acquired, Cost Method, excluding Commissions			$ 22,633
Stock Repurchase Program, Cost Incurred			$ 19