Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Consolidated Balance Sheets [Abstract]
Allowances	$ 49,364	$ 32,392
Series A preferred shares, par value	$ 0.001	$ 0.001
Series A preferred shares, shares authorized	1,000,000	1,000,000
Series A preferred shares, issued	200,000	200,000
Series A preferred shares, outstanding	200,000	200,000
Series A preferred shares, redemption amount	$ 203,000	$ 203,067
Series A preferred shares, liquidation preference	$ 203,000	$ 203,067
Preferred shares, par value	$ 0.001	$ 0.001
Preferred shares, authorized	4,000,000	4,000,000
Preferred shares, outstanding	0	0
Common shares, par value	$ 0.001	$ 0.001
Common shares, authorized	250,000,000	250,000,000
Common shares, issued	93,101,007	92,325,201
Common shares, outstanding	72,851,418	78,516,566
Treasury stock, shares	20,249,589	13,808,635