Share-Based Compensation - Nonqualified Stock Option Transactions (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2018 $ / shares shares
Number of Options
Options outstanding beginning balance (in shares) | shares	232
Exercised (in shares) | shares	(42)
Expired (in shares) | shares	(190)
Options outstanding ending balance (in shares) | shares	0
Weighted Average Exercise Price
Options outstanding beginning balance (in dollars per share) | $ / shares	$ 25.19
Exercised (in dollars per share) | $ / shares	12.17
Expired (in dollars per share) | $ / shares	28.10
Options outstanding ending balance (in dollars per share) | $ / shares	$ 0.00