Stock-Based Compensation and Other Employee Benefit Plans (Schedule of Activity, Restricted Shares) (Details) - Common Stock [Member]	6 Months Ended
	Jun. 30, 2019 $ / shares shares
Restricted Shares [Member]
Restricted Shares
Non-vested restricted shares, beginning balance (in shares)	1,270,233	[1]
Granted (in shares)	223,969
Vested (in shares)	(331,959)
Canceled/forfeited (in shares)	(5,650)
Non-vested restricted shares, ending balance (in shares)	1,156,593	[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	46.91
Vested (in dollars per share) | $ / shares	13.73
Canceled/forfeited (in dollars per share) | $ / shares	33.28
Non-vested restricted shares, per share weighted average grant date fair value, ending balance (in dollars per share) | $ / shares	$ 39.90
Restricted Stock Units [Member]
Restricted Shares
Non-vested restricted shares, beginning balance (in shares)	18,700
Non-vested restricted shares, ending balance (in shares)	3,600

[1] Includes 3,600 and 18,700 restricted stock units as of June 30, 2019 and December 31, 2018, respectively.