Stock-Based Compensation and Other Employee Benefit Plans (Schedule of Activity, Restricted Shares) (Details) - Common Stock [Member]	3 Months Ended
	Mar. 31, 2019 $ / shares shares
Restricted Shares [Member]
Restricted Shares
Non-vested restricted shares, beginning balance (in shares)	1,270,233	[1]
Granted (in shares)	221,462
Vested (in shares)	(326,346)
Canceled/forfeited (in shares)	(1,700)
Non-vested restricted shares, ending balance (in shares)	1,163,649	[1]
Per Share Weighted Average Grant Date Fair Value
Non-vested restricted shares, per share weighted average grant date fair value, beginning balance (in dollars per share) | $ / shares	$ 31.80
Granted (in dollars per share) | $ / shares	46.90
Vested (in dollars per share) | $ / shares	13.34
Canceled/forfeited (in dollars per share) | $ / shares	35.53
Non-vested restricted shares, per share weighted average grant date fair value, ending balance (in dollars per share) | $ / shares	$ 39.84
Restricted Stock Units [Member]
Restricted Shares
Non-vested restricted shares, beginning balance (in shares)	18,700
Non-vested restricted shares, ending balance (in shares)	5,100

[1] Includes 5,100 and 18,700 restricted stock units as of March 31, 2019 and December 31, 2018, respectively.