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Shareholders' Equity - Narrative (Details) - USD ($)
1 Months Ended 3 Months Ended
Mar. 15, 2017
May 15, 2016
Mar. 17, 2016
Mar. 31, 2017
Mar. 31, 2017
Common Shares          
Class of Stock [Line Items]          
Stock repurchase program, authorized amount (up to)     $ 150,000,000    
Stock repurchase program, period in force 12 months   12 months    
Stock repurchase program, amount not utilized       $ 106,600,000  
Stock repurchase program, additional authorized amount (up to) $ 150,000,000        
Number of shares surrendered to satisfy tax withholding obligations (in shares)         6,694
Series E          
Class of Stock [Line Items]          
Stock redeemed (in shares)   11,000,000      
Redemption price per share (in USD per share)   $ 25.00      
Preferred stock, redemption amount   $ 275,000,000